I enjoyed this.
Nice clean, simple graphics.
I found the cooldowns a little too much, but that is just me.
The graphics for the enemies feel a bit flat (dimensionally) to me and could do with a bit more shading, but overall I enjoyed the graphics.
The enemies could have done with some animation for jumping onto the main platform, rather than the peculiar gliding they seem to do.
Overall, this is a good simple game!