Hi zatomeisis, this was a fun little tower defense demo!
I have to admit I did get a little confused at why the wave was taking so long to find its way down after I started it, until wave 3 when I jumped up and saw the scope of the level. Unfortunately though (and this might be remedied later on in the game) it felt to me the optimal solution was just to put everything on the bottom of the map next to the tower and just sit there and assist with shooting myself.
I don't mind the game being played totally on the keyboard, but having to switch over to mouse controls to purchase a tower felt a little jarring and I thought something had broken at first.
The boss felt a little disconnected from the other level, it felt fine per say but it really felt like I had stepped into a different game, maybe adding some options for the player to throw some towers down would help?
This sounded way more negative than I intended and I definitely did have fun with the game. And just finally wishing you the best for the rest of development!