Stringent level evaluations that stifle progress. Two examples: Action Henk and Giana Sisters: Twisted Dreams.

Both games evaluate you at the end of each level. If you don't score enough stars, then you can't unlock required boss levels. You then hit a period where you need to "git gud" and replay super tough levels to the point of insanity, all so you can earn more stars. Giana Sisters takes this to the next level by putting you through way overlong stages, and only counting stars within the same world towards you total. In other words, if you want to unlock the boss level in world three, then you need stars from world three levels. You can't go back to the easy levels at the beginning of world one to earn stars.

I don't mind the challenge, honestly, but both games are difficult enough that they don't need the added stress of forced evaluations on top of that. It really just drags the whole experience down.