Its a really good game but with a few flaws that stop me from giving you a 5 star rating. If you make a sequel or an update I would like to give you a higher rating, if you fix these flaws.
1. You need a storage box of some sort at the base. Because there is no storage box of any type you have to carry around a lot of crafting items. Now I'm not saying that you have to make it so that when you are crafting that it auto-uses them from the storage, just add a storage so you don't have to waste space, because its really annoying when you are having to manage items while you are in the middle of a mission because you don't have enough space to carry anything else.
2. You have potions yet you can't use potions in battle zones. Why? Yes, the enemies do drop health packs but sometimes you need them right then and now but there is no health drops. Make the potions for anytime use.
3. Rare, if ever, crafting items. Now I'm not saying that you need to increase the drop rates. If you want to keep them super low go ahead, but let people know that its a rare crafting item so they don't throw the item away not realizing that it was a rare item they needed to make said item, or make it so that people can buy them for a really high price. One or the other will really make this game a lot more fun.
4. Quick weapon switch. Not much to really say, add a button that lets you quickly switch from one weapon to another.
I think that pretty much covers all the major complains I have. Really, the item storage is one of the most hindering things about this game and it really stops it from being a great game. Its really good just not great.