The game is too hard, Howly (your pet black hole) gets overwhelmed very quickly and easily. Your only means of defense (the black hole gun) is not effective at stopping the horde, requiring pin point accuracy at all times.
Also the fact that you need to leave poor Howly behind to feed it, makes it even harder as leaving it alone for even a few seconds exposes Howly to great danger.
But the 3D graphics is pretty neat, and the premise is actually quite interesting. (protecc the pet black hole)
Maybe you can make a cute black hole character for maximum "must proteccc".
All in all, a neat shooter game but quite frustrating.