Great pixel art work, I really liked it!
I found the game fun, although it didn't take long to get buggy. However, I managed to play it long enough to enjoy it.
I would suggest adding non-autoexecuting powers, that have a cooldown and can be used whenever you want. I think that would reinforce the idea that you're the boss (I'm not a big fan of this genre, so I don't know if this would somehow conflict with any of the other mechanics).
Another thing I tried was to get enemies stuck on rocks and other obstacles on the map, but it turned out they were just part of the background. Maybe that could be explored as well.
I didn't understand the "combine" mechanic, I don't know if it just doesn't work or I just don't know how to use it, haha.
The font and layout of the text are a bit confusing, I think that could be improved.
I really liked the sounds and music!
Good job, and I hope the feedback helps! Good luck!