When you first open Army Men Strike, the game guides you step-by-step through the initial levels of the game. This tutorial is very thorough, and following it is the best and fastest way to increase in level.

The tutorial starts automatically when you open the game for the first time. It starts with a storyline that you must click through, then it opens into:
Chapter 1 - First Victory

You are first prompted to click on your Chinook, which takes you to your first Special Operations task - The Commander Returns. You have the option to skip the tutorial at any time (a "Skip Tutorial" link appears in the upper right corner), but following through the tutorial is best if you are new to the game.
The tutorial walks you through a Special Operations battle, and shows you how to use a skill weapon. It then shows you how to deploy troops. It's very easy to take the HQ and win the battle.
You are then taken back to your Command Center, where it walks you through the four quests in Chapter 1. Your first task is to upgrade your HQ to level 2, which it shows you how to do. You can then collect the reward for that quest. Upgrading Tank Camp to level 2 is next, and also a 1-click quest.
Next is back to the Chinook to clear another Special Operations Stronghold. This time you have to do it yourself, there are no prompts. Deploy Murphy and use your Vulcan Missile skill (the red bomb icon) to take out the enemy positions. Your troops will then head to the enemy HQ and take it out. You'll gain a level 3 Training Dummy, and 10 fragments for officer Victoria.
Next, the tutorial takes you to the Recruitment Center, and it gives you a free Normal Recruitment try. Your reward will be a new officer: Bull.
The last quest of Chapter 1 is to upgrade the Chinook to level 2. Again, this is an easy 1-click quest. Completing it allows you to complete the Chapter, and gain the rewards: a level 5 Training Dummy, 100 Basic General Material, and 100 level 1 Deployment Material. These all help you increase the power of your officers.
Chapter 2 - The Commander Returns

- Upgrade HQ to level 3 - this quest shows you how to use speedups to finish a task quickly.
- Build a Copter Camp - the tutorial points out an open space on the floor of your Command Center, and prompts you to place a Copter Camp there.
- Train 10 One-Man Copters - Before you train, you must place an Army Tent. The tutorial takes you to an open space and prompts you to build one. Next, go back to the Copter Camp and train up some level 1 copter troops, called One-Man Copters. Make 10 of them.
- Clear Special Operations Stronghold 4 - Back to the Chinook. This time you'll have to spend some plastic resources to open a new section of the Special Operations map. Spend 400 plastic pieces to open up Strongholds 3 and 4, then attack them both. Since you now have 2 officers (Murphy and Bull), the tutorial will show you how to add a new officer to your attack. Bull adds a new skill: Healing Kit. Before you can take on Stronghold 4, the tutorial tempts you with a new officer, but it's one you have to spend money on - Wendy. 3 quick taps of her Divine Halberd skill and you've cleared the level. The tutorial then offers you the chance to recharge some gold, which gives you Wendy as a bonus reward. Decide if you want to do that or not, then continue on to Stronghold 4. The enemy positions here are stronger, so you'll probably need to use your Vulcan Missile and Healing Kit skills to help you win.

The tutorial now shows you how to improve your officers. It takes you to Murphy, and shows you how to Upgrade him. By now you have some Training Dummies, and it shows you how to use them to increase Murphy's Level to level 10. Once you've done so, finish off the Chapter.
At this point the tutorial tells you that you need resources to continue on. you have a choice here: Battlefield Gathering or Base Construction. Both are useful, so pick one and follow it. For purposes of this walkthrough we will choose Base Construction.
At HQ level 3 your Defense Factory is unlocked - it's built in the open space to left and down from the Lab. The Defense Factory allows you to build traps that will do damage to any attacking players.
Chapter 3 - Inner Man
- Upgrade HQ to level 4 - The tutorial first takes you to your HQ to upgrade it, but wait - there's a dependency that hasn't been met. Two of them, actually: your RC Plan needs to be built to level 1, and your Chinook needs to be upgraded to level 3. The tutorial prompts you to go to these buildings to upgrade them. First you build your RC Plane, then your Chinook to level 3. Then go back to your HQ and upgrade it to level 4. This is a 40 minute task, and the tutorial urges you to use speedups to accelerate it. It's up to you whether or not you wish to do so. You can perform the other quests while waiting.
- Clear Special Operations Stronghold 6 - Go to your Chinook, and spend 800 plastic to unlock the next section, then conquer Strongholds 5 and 6. If you decided to purchase Wendy, add her as an officer and use her Divine Halberd to clear the mines. After you finish Strongholds 5 and 6, the tutorial shows you how to Promote your officer Murphy. This gives him a 2nd gold star, and opens up his first Battlefield Skill - Commando Attack
- Research 1 Technology - You have to have HQ level 4 before you can add your Lab, so make sure you've completed the first quest before this. Follow the prompts to place your Lab, then follow the prompts to research Legion I.
- Unlock 1 Building Plots - Clicking on the quest takes you to two open Building Plots. Spend 2000 paint and 2000 plastic to open each up.
- Have 4 Plastic Factories and Paint Factories - Follow the prompts to build the required Factories.
- Basic Production of Plastic reaches 300/h - You will need to upgrade some of your plastic factories in order to reach this goal. The tutorial walks you through doing so. You will notice that you can upgrade quite a few levels for free

Now that your HQ is level 4, you can go to the Battlefield. To get there, click on the binoculars icon in the lower left corner.
It's important to note that you can now switch Battlefields. From the Volcano Force support site :
"You need to get a Newbie Teleport to switch to another battlefield.
When your commander reaches Level 4, you will be rewarded 2 Newbie Teleports. When your HQ reaches Level 6 or you have registered for more than 6 days, your unused Newbie Teleport will be removed and you will not be able to teleport to another battlefield any longer.
On battlefield map, you can tap World Map icon to view all the battlefields.
After selecting the battlefield, commanders who meet the requirements can move into this battlefield.
Commanders who fail to meet the requirements on HQ level and registration time can start a new game to move to another battlefield through this way. All current game progress will be lost after you start a new game. Therefore, please bind your game account to a Google or Facebook Account to keep your game progress."
To go to a specific Battlefield, go to the World Map (using the icon shown above) then use the Search icon in the upper right corner to find the Battlefield you wish to join. Click the Battlefield you're interested in, and click on that icon. Select an open spot on the map, and click on it - you will see a button that says "Join Battlefield"
By now you will have some Training Camps (Copter, Commando, and Tank), and some Resource Factories. Get them all working for you. Upgrade them to the highest level you can for free. For the Training Camps, get some troops started. Go to each of them and train the maximum amount of troops it will allow you. Always have your Lab working for you - go there and start Researching things. You should also be able to upgrade it to level 3 for free. Make sure you have filled all of your open Building Spots. You should have 2 Army Tents, 2 Hospitals, and 3 each of Plastic and Paint Factories. Always gather your resources! You will see a small plastic piece or a paint drop above your factories - click on them to collect your free resources.
You can also start attacking Toys now. Go to the Battlefield and click on the little treasure box in the lower right corner. Click on the paw icon, and search for a Tan Army. Click on it, then Attack. Your officers and troops will be selected for you - click "Deploy". By attacking 1 Tan Army Toy you will gain one Commander Level. The tutorial will then walk you through how to spend the 2 Expedition Talent Points you earned by increasing your Commander Level.
You will notice that each time you increase your Commander Level your Stamina is refreshed. You have a maximum 10500 stamina when you start out, and you spend 1000 stamina each time you attack a level 1 Toy.
You will also notice that when you attack toys some of your troops are wounded. Go to the Hospitals in your Command Center, and Heal them.

Gaining Commander Level 4 gives you 2 Expedition Talent Points and 4 Command Talent Points. You can spend the Expedition points, but Commander Talent Points aren't unlocked until Commander Level 5.
At this level, while each attack does do some damage to the Tan Army Toy, it doesn't kill it completely. You can keep attacking the toy, doing more damage, until it dies.
Commander Level 5 gives you 1 Expedition Talent Point and 5 Command Talent Points. This also unlocks Command Talents, and you get to make an important decision: you need to select your Command Medal I Ribbon Talent Buff. You can select from Increased Construction Speed, Increased Technology Research Speed, or Increased Unit Training Speed. I feel that Construction is most important, so I suggest you select that buff. Note that your first selection is free, but you can change it later - however you have to spend 200 gold to do so after the first free selection.
You will also notice some icons to the upper right of your screen, and you may notice red dots in their upper right corners. These are tasks that are available to you, and frequently they give you free things. Of most interest are the Event, Bonus, and 7-Day Training icons. Click on each of them and look around the screen for red dots. Click on everything with a red dot to see if it gives you something free - almost all of them do.
You can also check your Mail for rewards. You get rewards each time you attack a Toy. You will also have a number of free rewards under the System mailbox. Look for the messages with tan rewards boxes to their left, open them up, and click "Claim". A quick way to claim all of the available rewards is to click the three dots in the upper right corner, then the "Select All" box in the lower left corner.
Commander Levels 6 and 7 are easily achieved by attacking more Toys.
The first big decision you make is at Commander Level 8, when Expedition Medal II opens up - SELECT LOSSLESS EXPEDITIONS! This means that when you attack toys you won’t get any wounded troops - this greatly reduces the amount of resources you spend when you attack toys, because you won’t have to heal your wounded troops.

Next let's check out the VIP section. This is a box in the upper-left corner that says VIP1. It's gold when activated (you start out with 1 free day of VIP status), and grey when your VIP is not activated. By now you will have gained rewards that give you free VIP points - use them, and you'll almost certainly gain VIP2. Each VIP level increases your abilities in some fashion - click on each level to see what it gains you.
Try to use your stamina up by attacking toys. At Commander Level 8 you can select Lv. 2 Expedition Mastery, which allows you to attack level 2 Toys. Attacking a level 2 toy costs 1500 stamina, but it gains you 5000 Exp. Higher level toys also mean better rewards.
Commander Levels 9 and 10 come quickly, especially if you are attacking level 2 toys. Commander Level 10 opens up a Command Medal II Talent Ribbon, and you select from Extra Damage Taken (reduces the amount of damage your units take when you are attacked by someone else), Extra Attack Speed, or Enhanced Critical Strike. I like to chose Attack Speed here.
When you start the game you are provided a free 3 day Aegis, already activated. This protects your Command Center from being attacked by other Commanders (players).

Keep attacking Toys, gaining Commander Levels 11, 12, 13, and 14. At Commander Level 14 you will finally run out of stamina and will have to wait until it replenishes.
It's important to keep your building levels as high as your HQ Level allows - go around your Command Center and look for buildings that have a blue arrow near their level marker. This means that the building can be upgraded, and that you have all the requirements necessary to do so. Upgrade your Resource Factories, but don't forget the other buildings, such as your Training Camps, Defensive Line, Parade Ground, and RC Plane. Your Moneybox is available to upgrade as well. Many of these can be upgraded for free, with no time or speedups.
Since attacking toys and upgrading buildings each have some time that needs to expire, alternate between the two. Attack a Toy, then go in to your Command Center and start a new Construction task. You can also go to your Chinook and attack Strongholds. Unlock areas with plastic as necessary. Once you clear Stronghold #8 you will gain a new officer: Victoria.
Chapter 4 - Mad Science

- Upgrade HQ to level 5 - Your Chinook needs to be level 5 first.
- Clear Special Operations Stronghold 8
- Attack 2 Evil Toys
- Upgrade Hospital to level 2
- Build an Artillery Camp
- Upgrade Army Tent to level 2

Once you reach HQ Level 5 the tutorial will take you to the Quests interface. There are "Recommended Quests", "Daily Quests" and "Achievements". By this time you will have accumulated a handful of all of these - look for red dots, and collect the rewards you've earned.
Chapter 5 - Shoulder to Shoulder
- Upgrade HQ to level 6
- Clear Special Operations Stronghold 11
- Attack 3 Evil Toy
- Join Corps Once
- Participate in Counterstrike 1 Time
- Train 100 Grenadiers
After an hour or two of play, you should be:
- HQ level 5
- Player level 14
- VIP level 2
- You should have Murphy, Bull, and Victoria up to level 10 (I got lucky to get Dr. S)
- You should have the following buildings:
- Moneybox lvl 3
- Defense Factory 3
- Copter, Commando, and Vehicle lvl 3
- Chinook lvl 4
- Parade Ground lvl 4
- Defensive Line lvl 4
- 2 lvl 4 Hospitals
- 3 lvl 5 Plastic Factories
- 3 lvl 4 Paint Factories
- RC Plane lvl 4
- Lossless Expeditions so attacking toys doesn’t wound your troops.
- Completed Chapter 5 of the walk-through