The game as a whole was OK, but there were a few things that brought it down.
The combat system was very awkward at first, and took a few times to get used to it. Movement through the levels was also... strange at times. It would also appear that the command for double jump is either incredibly finicky, or outright broken.
The whole 'solar powered' concept was interesting and inventive, and the upgrade from each downed enemy was good as well.
Apart from the game's movement system, it's quite a playable if not enjoyable game. That'a all I've got for now.