This was a fun game
For the jump, it really felt good, as in the height control and double jump were good and felt nice!
But, when u land with some horizontal velocity, the guy slid a bit. It needs more friction in that place i think
Other than that, the highest I could get was 15 letters xD I didnt know the quota nor the time remaining so it was a bit hard to keep track of all that.
But overall, its a good game with some great pixel art! Id say the map tiles just need some more variation, it already looks good! and as another commenter suggested. A backdrop could also make it look better
You did a great job! :D