The first world was pretty meh, jumps were too tight, checkpoints took forever and there were quite a few blind jumps (I think 3 right before a checkpoint, the one after a checkpoint was honestly fun).
But World 2 was quite passable, I had serious fun with it.
There's a few fixes I would reccommend that could improve the gamefeel easily. First off the enemy hitboxes are far too large, they should be like half the size. It is no problem to have the player slightly clip into an enemy, but the player should never be damaged while not touhing the enemy, in general it is good practice to just have hitboxes be smaller than enemies.
Then there's definetly a need for a coyote timer. When running off a platform you should still be able to jump for a little while, though it can be a bit tricky/scary to implement (I haven't done so yet myself). Usually players will try to jump at the last moment on a tight jump, but human reaction time ends them up after the platforms end. So it is common to add a little bit of time afterwards (Human reaction time is around 0.25 seconds for reference, so you should play around with a coyote time of around that range)
I also noticed a simmilar issue to something I had in my own recent game. When you respawn you will instantly move, which made me fall of platforms after getting hit easily. That's also caused by reaction time, I fixed it in my game by adding a 0.3 second time of no movement after respawning. I would reccommend trying to implement this before a coyote time because it is very simmilar to it but a little easier to implement.
But overall while the game is nothing special the second world had me a bit surprised with how interesting some of the level design seemed. Keep on with that.
(Also I was able to hit the giant coin with some ptoper jumping, sadly don't have a screenshot)