- As an action game
It's good, I like the whole corrupted sector concept, but the AI feels too sluggish. I couldn't understand what the induvidual powers did, either, but used them anyways. Also, the two levels felt identical, with the same enemies and boss. But, I believe you can improve all of these.
- Is the game balanced?
As far as balance goes, the game felt too easy. I rarely lost health. At some points, the sheer number of enemies coupled with the small size of rooms provided some difficulty, but the boss was too easy. (Maybe give him a melee attack too?)
- Easy to keep track of things during combat?
Mostly. Player health and enemy positions were simple to keep track of, but enemy health wasn't as all the enemies bunched up together. Ability cooldowns were fine, but since I didn't know what they did, I just kept cycling them.
As for AI...
I'm not really sure how. Since the rooms are already quite narrow, there's less scope for convincing enemy AI. Maybe you could add extra enemy types, like one that heals other enemies.
For the boss, you should add a melee attack or something. Maybe add boss stages, triggering when health goes below some level.
You should probably go through a few articles on Boss design. Those will help.
Overall, pretty good concept you've got going on. With a little more polish and a few additions, this could be great! Just think it through.