I couldn’t actually play the game nothing seems to happen? sadly! visuals look great and it sounds like a neat idea!
Ah darn, sorry about that, perhaps it's an incompatible thing in the project (I did use a couple of large textures).
Btw I added a note in the description of the game for a workaround, it's a bug that happens depending on how fast you buy and place the first "tower". If you do that quickly, the enemy spawning works as intended.