I really didn't understand what do to at first. Including a tutorial in-game would make it much better.
But when I got it... dang, it just doesn't let the player rest! I couldn't even get soldiers to the spot because enemies spawn constantly! Some kind of pause when exiting a soldier and opening the shop would be nice.
The idea of separating soldiers didn't really work since only one can be controlled at once. Try different controls!
Bugs: trying to merge with no soldiers stops the soldier forever; sometimes only having one soldier or one cube destroyed ends the game.
It's really not bad, I'd love to play it if it wasn't that difficult!