Thank you for playing! <3
Interesting... we will look into the issues. I recommend you still give it a second chance, since you can always restart a level by pressing "P" (for Pause) or the Escape key (although that beams you out of fullscreen... haha, I recommend pressing "P" :D). You can only change the units before the bell.
I'm glad you like our art style! Yeah, from afar it's kind of pixelated, but you can always zoom in and out with your mouse wheel! :)