Yeah for sure! I don't think the fourth level was actually harder objectively than the third level. I actually didn't have a big problem with levels being difficult, but rather them being tedious. On the third level, I'd spend quite a fair amount of time figuring out the puzzles (which were great!) and that had that nice sense of difficulty and problem solving. What made the level make me groan and want to close my tab was when I caught a stray fireball because I messed up a jump slightly. The same principle is what made me a bit offput to level 4 too. I actually got through first try, but the stress of trying to maintain my health so I wouldn't have to do everything over again as I was solving the puzzles took away from the puzzle solving experience to me.
But I don't think the death mechanic was all bad, not after seeing the boss level. Since the boss level had an air of "you can die here" and the puzzles themselves didn't take too long to do again and actually emphasized more the mechanics of movement rather than a long Rube Gobert sequence of steps, it made the action more enjoyable!