It's interesting going back to this to see what does and doesn't hold up well about it. I'm playing it coming off the back of replaying Celeste, which is all around just a much better game, and certainly didn't help the case for Meat Boy. I think the most core problem is that the movement here feels good to go fast when it's working out, but the slipperiness and inconsistency of it becomes very frustrating in harder levels. That combined with the type of difficulty used in the later level design makes for a pretty bad time. I breezed through the first couple of worlds and felt like it was holding up pretty well to my memory, even if it does have a few too many filler levels. The later levels don't feel like they're demanding mastery over the controls and moveset though so much as making you fight against it, and introducing gimmicky mechanics that don't feel fun or consistent. Having to hold jump for just the right amount of frames coming out of a wall slide at a certain speed so you have just the right amount of momentum so that you can make it through a tiny gap between sawblades isn't fun. Now make a dozen jumps that precise on some of the later levels.

It's not just that it's difficult, as I mentioned replaying Celeste recently, that game gets more fun as it gets more difficult, because your moveset in it feels reliable and like you can replicate any movement consistently, and the levels feel designed around it and not against it. That's the part of this game that makes it feel really dated to me. There are older platformers out there that still feel good but it's a certain type of difficulty in design from around this time, mostly popularized by this game, that I just don't have much patience for these days.

For some side notes, the instant respawn and the end of level replay system are really good, and more games should have both of those. I didn't go for many of the collectibles or side content this playthrough, as I did already do all of them back in the day but they also felt like leaning even more into that style of difficulty I dislike. What little story and humor there is also feels very dated.

Overall, I dunno, this seems a little harsh. I did enjoy this when I originally played it and it did help bring pure platformers back into popularity, but now there's so many others you can and should go play before this.