This was a cute little game, the art is nice, jumping feels ok, and I really love the text popping up from the rabbit in the crate!
I agree with the other comment calling the crate dragging a little floaty. I get thats part of the difficulty though so I suppose really depends on intent. After all having it kinda floaty prevents the player from just using it as a floating platform to skip the level lol.
I did like how the mechanic was expanded out to be usable on other crates for the longer spike puzzles. It kinda lef tit up partly to the player how safe they wanted to paly it with shorter vs longer jumps.
I admit I'm not a huge fan of platformers in general so I'm not really the target audience and couldn't tell you what could be done better, but it was a neat little game. Good work!