Tried the game and I have a blast laughing on the goofy stuff I made. Control is pretty good to be honest. I am not really a platformer player. I just played super mario when I was a kid and thats all so I cant really say much about this kind of games. I would ask you though is this a rage game? WHAHAH because it achieved its goal for me atleast in the later parts. kinda got stuck on the slime I thought I could cheese it out but after 20 attempts I found the correct route to take.
Game is pretty good, artstyle is good along with the tileset you chose. it is very good and you can get immerse in it less the dying part WHAHA.
Some suggestions I could say is that. work on the sound effects. try to include some to give it some more life. try to add a mainmenu to hook players into it not just straight into gameplay. like you throw the player into an open world and nothing. create some tutorial levels to explain the mechanic abit more. Work on the UI too. FYI. the death counter UI is broken It doesnt dismiss the past counter and just stack it. for example in my playtest I died a lot of times. and it is just layer and layer of V and X in there stack and stack WHHAAH.
overall, the game is great and I could see that you gave it alot of time and love. goodluckk on your future games