For all the trial-and-error gameplay and hilariously mean and petty traps, I think what makes IWBTG hold up surprisingly well a decade and a half later is that there is a genuinely really enjoyable click and feel to the platforming. Something really fun about being basically a flea trying to navigate a universe that wants you absolutely dead at absolutely every turn. Plus, weirdly satisfying jump sound, honestly.
Of course, there's quite a lot about this game that screams "amateur freeware game from 2007", from being extremely buggy and unstable (though the fan remaster fixed that at least) to having quite a few really shitty parts that stick out like a sore thumb even for a game designed to be as obnoxious as possible. That Bowser boss fight in particular is a real crowning example of "this isn't even hard, it's just really tedious".
Regardless...it's a classic, in its own, weird little way. There's a reason every YouTuber in the 2000's did a rage-through of it and why it's proved to be a pretty influential game in the long run. For better or worse.
Of course, there's quite a lot about this game that screams "amateur freeware game from 2007", from being extremely buggy and unstable (though the fan remaster fixed that at least) to having quite a few really shitty parts that stick out like a sore thumb even for a game designed to be as obnoxious as possible. That Bowser boss fight in particular is a real crowning example of "this isn't even hard, it's just really tedious".
Regardless...it's a classic, in its own, weird little way. There's a reason every YouTuber in the 2000's did a rage-through of it and why it's proved to be a pretty influential game in the long run. For better or worse.