Cool! I like the fact that only one little guy can be controlled at a time making so that you have to try and have as little downtime as possible. The UI of the start menu also felt very clean and doing just what it needs.
The size of the game window was a little too small for my taste, I struggled to click on the little guys on several occasions.
Adding a little bit of juice (sound effects, particles, animations) and a clear win condition would make this great. I hope you consider expanding on the idea, I think it has great potential.