Very interesting game, love the genesis (?) style. i enjoy it but there's something that i wanted to point out
at the early part of the third screen (the one that you put in second screenshoot ) the pit is filled with diamond and you not died if you go down there, but then later on part where you burn boxes to open a hole, you died if you fall. because the first pit is safe i thought it this pit would lead me to a secret room or something XD i think it's better to turn it into a spike pit rather than bottomless pit
btw please add frameskipping, it's not your fault but it's really slow in my laptop