I've been stuck on the final boss for a while now. I've amassed around 2,600 deaths over 30-odd hours playing. I find it quite amusing.
It might just be the right kind of personality type to play this game; you have to not only agree with the motto "Losing is Fun!" but you also have to have a nice healthy streak of masochism and stubbornness.
If it wasn't such a bright, colorful, visually appealing game with lots of nostalgic areas, great music, solid platforming controls and the like, I probably would have given up before the first boss. But something just appealed to me to keep playing, figure this out, navigate this maze, kill this boss. Perhaps I am just too invested at this point and I need a psychological payout. However, I'm not obsessing over it. At this point, I play for a few deaths to the final boss and put it down to try again later.
There is definitely something to be said that IWBTG has probably a dozen or more fangames and tributes. Perhaps it's the black humor; the futility of arbitrary deaths; the moon randomly falling on you or the upright spike flying sideways. It's like a running gag that stays far past its welcome and becomes irritating, then keeps going until it transcends the boundaries of humor. I've been stricken by bouts of laughter after a series of unfortunate deaths. (I'm fairly certain I found it legitimately funny, and I wasn't just laughing to keep from crying or anything)
Are the deaths random and unavoidable? Nearly all of them are, at first. It doesn't take any real conscious memorization, after it kills you a couple of times, you just sort of remember whether you like it or not. Once you get past the "random surprise death" stage, the game becomes one of pixel-perfect jumping and hyper-accurate timing and spatial judgement. Therein lies the reward, the "I'm good enough at platformers to play I Wanna Be The Guy", the mental pat on the back as you best fruit, spike and moon and become The Guy.
OH MY GOD FUCK DRACULA HE'S THE WORST BOSS EVER. IT'S SO AWFUL, A GAME BASED ON MEMORY AND PATTERNS, THAT THEY JUST HAVE A BOSS WHO RANDOMIZES HIS LOCATION AND ATTACKS. UGH. HE KILLED ME MORE THAN ALL OF THE OTHER BOSSES COMBINED. FUCK DRACULA.