Given that the game is free, expect some in-app purchases present in the game. The good thing is that the game is not that restrictive about its content regardless if you won't purchase any of its IAPs. Some purchases in the game are somewhat really helpful and are reasonably priced considering that you get the game for free. Although in all honesty, Gold Coins in the game are outrageously priced.
IAPs can be accessed in the item shop and picking on the "specials" tab. Gold Coins on the other hand can be purchased directly on the Coin Shop inside the "shop" (shop button in the town screen). Nonetheless, here is the list of IAPs found in the game.
Unlimited Stamina ($12.99) - Your battle stamina will not decrease. If un-availed, each chapter will cost 1 gem to perform and each of this penalty gem takes an hour to recuperate. You have a total of 5 gems by default. This is a one-time purchase and will permanently grant you unlimited times to perform missions. Especially effective when you've reached higher levels / chapters in the game where you are limited by your move points / turns participating on battles.
Auto-charge ($4.99) - This automates your field planting (if you have the consumable items to do so) and product manufacturing (again, if you have the items to do so). Additionally, purchasing this will also auto-collect your products, spawned meats, and cash resource (from generating facilities). Relatively useful when you already have a big town (meaning you have many buildings, farms and facilities) and farming and stuff becomes a rather tedious chore.
Hero-pass ($9.99) - Purchasing the hero-pass includes an number of benefits to players including:
1. No adverts (except if you wish to view one in exchange for gold coins)
2. Automatically receive 50 Gold Coins daily
3. Friend Cost limit increased by 25 points (rather useful especially when creating more teams to patrol)
4. Meaty Chunks carry limit increased by 25 units (useful in battles to avail help commands)
5. Money Limit increased to 2500
6. +1 Battle team (free of friend costs)
7. +1 Patrol team (free of friend costs)
Gold Coins Packages (starts from $1.99 up) - will earn you additional Gold Coins (packaged in 200's, 800's, 1500's, 4500's quantities). Mainly used to purchase spins in the lottery which ultimately earn you new Hero Morph Suits or Megabots.