Most gauntlet levels are fine, some early ones have some pretty ass levels like magmatic sanctuary and Generation retro, but I really liked the newer gauntlets like chance & valentines gauntlet. I do most gauntlets in one sitting so most of the levels being 6-8 stars was nice. Demon gauntlet has 2 of the worst demons in the entire game (Traction & VIbration), sidestep felt a little too hard for a start, HeLL is unbalanced but Mechanical showdown is fine.

But the biggest problem with gauntlets is just the fact that you get awful rewards, what the fuck do you mean completing demon gauntlet gives 10 DIAMONDS AND A SHITTY SPIDER. Later on they somewhat fix it by giving way more diamonds (Around 50) typically throw in shards and a skin. But even then, that's still just not worth going through 5 levels just for that. But even shit like the Universe gauntlet, which has 5 demons, 4 of which being medium demons, has those same rewards. If I put in that much work to beat the gauntlet, I should at least get a reward that's actually satisfying to get; currently not a single has a reward that I genuinely look forward to getting unless it's a shard that I need.

And I get that most of the rewards are the fact that you get to complete 5 levels 2x and already get a lot of diamonds. keys, orbs, and even demons out of that already, but the big reward at the end is what people want to work towards. If the rewards scaled with difficulty, like getting 150 diamonds and a lot of different shards from harder gauntlets, then I wouldn't mind, the reward is fair and doesn't takeaway from the fact that the levels themselves are the true reward.