This is alright... But a few things: Add descriptions SOMEWHERE that's easily accessible that tells you what the upgrades do, Also give us some numerical statistics of what they actually do. Also make the speed up button a toggle not a "hold down" this isnt' a mobile game.
ITWASAFINGER, That's what a strategy game is ABOUT. You build up an army to wipe out and crush the resistance in anyway possible, I've gone through this entire game without focusing on my economy, Hard as hell? You bet your sweet ass it was! Satisfying to beat every level like that? Damn straight!
Free items: When in a floor walk back and forth between two rooms[Easier if you've cleared the floor] if you keep doing this there's a random percentage chance a chest will show up and give you a random item, Rinse and repeat as many times as needed, + This so everyone can see
Sniper tower's OP....Buy nothing but the thing that gives you 200$ extra each time you buy it...Set up sniper tower, Increase rate of fire then damage then range...By game 4 you've got one that's almost full maxed out right at wave 1....Get 3 set up and you win the match period...
 "The Last Shelter"){kind=icon}
 "Creeper World: Evermore"){kind=icon}
 "NyanCat Idle"){kind=icon}
 "Coinbox Hero"){kind=icon}
 "Crystal Story"){kind=icon}
 "Creeper World 2: Academy"){kind=icon}
 "Cursed Dungeon"){kind=icon}
 "LRD: Rebirth"){kind=icon}
 "Murloc RPG 2: Episode 1"){kind=icon}
 "Frontline Defense 2"){kind=icon}
 "Trap Master"){kind=icon}
 "The Leon Wars"){kind=icon}
 "Towering Forever"){kind=icon}