If you get attacked before building any troops the Formation Setup window pops up and won't close until you move troops around. Without any troops to move you can't close the window. This essentially locks the game because there isn't a way around it.
It looks like a great game but why would you EVER want to require a mouse click for each swing rather than just holding down the mouse button to continue attacking? I'm sure many people will continue to play because the game is otherwise fun, I'm just stunned anyone would approve of that one design choice.
I would recommend that you enlist a native English speaker to assist with tutorial translation. Currently, getting started is a process of trial and error and this limits your potential audience.
Got a chance to play again after a while and I see a lot of improvements. Much better graphics, more dungeon layout variety, shields, and you can now drop any inventory item. Good work, sir (or ma'am).
Please alter the interface to allow unit purchasing with the number keys (or something similar). Either that, or make the towers toggle on/off so that you don't have to constantly press X or space to fire. Currently, you must switch between the mouse to buy units and the arrow keys to aim the towers, which is annoying and unnecessary. The P key for pause would be nice, too. Otherwise, it's a decent game.