Ok here we go!!
1)Add a fixed speed button x1 x2 x3 x5 etc.
2)Maybe add more towers
3)Make tiles on which towers can be placed,i was just placing a tower on top of another and i made a corner where nothing could pass
4)Add better graphics
5)Add difficulty settings
6)Add enemies of different categories (heavy armor,immune etc)
7)Fix some bugs (at a wave the enemies just stuck in a corner)
8)Make spread tower placeable to fixed locations,i spammed them so much that the game was ridiculus.
Thats for now :)