Personally I enjoyed it more than most people and apart from some of the needle sections, its actually not bad, plus the music is nice. Worth a play just for the weirdness.
For the nitty gritty, just read Whalington's review.
Boss fights-pretty mediocre and are generally just one attack. You refight the same boss sprite a few times with different and then fight a different boss sprite. Final boss is these two sprites with one final attack. One is pretty cool and the other sucks pretty hard. Kind of boring but it's decent
Avoidance segments-First one consists of dodging incredibly slow moving orbs. Really really boring. Second one consists of avoiding the same attack for 60 seconds of orbs being pulled into the center of the screen. Also boring. Both are pretty easy and pretty dull.
Needle-Starts off decent(there's a pretty fun one where you have to dodge orbs while puzzling) but the last two are ridiculously stupid and would be impossible to do in normal mode reasonably honestly. One has a sphincter drop followed by a steak jump into a ledge, the other one has a floor diamond, a diamond, and a ceiling double diamond along with a bunch of other pretty garbo jumps. No reason at all for these stupid hard needle segments to be there since all they do is eat up your hp(but it doesn't matter because the game's easy anyways).
Good idea, poor execution with lazy needle design, very boring avoidances, and okay bosses. Not really worth your time