start button should be bigger - i spent like 30 seconds trying to figure out why the avatar didnt move with wasd or arrow keys before realizing the game hadnt started yet, and this was even more confusing when i had to click "start game" on two separate screens (they were pretty looking screens at least tho!!!)
woahhh these instructions are too much at once and too crowded!!! make a few blank tutorial levels and explain all these things as they come up instead of pushing it on us all at once. maybe instead of having the player click through 2 screens and then a path selection stage you could just have one title page and utilize this space to more gradually feed the player instructions.
bullets still flew forwards when i was facing backwards
the jump key was z in the path select and x in the stage? confusing but i figured it out almost instantly so no big deal its just weird
jumping only went directly upwards unless i pressed the directional keys simultaneously. this works for some games and in a lot of ways it makes sense, but given the rigidly square nature of your platforms it only serves to be a little frustrating instead of bringing about a sense of realism or real physics. i highly recommend you allow characters to move in midair if you allow double jumps/etc and changing directions in midair otherwise. it just doesnt make sense that i can turn around if im already moving horizontally, but am unable to do so when going straight up.
cool music, animation is simple but cute despite having literal and figurative rough edges
the speed in midair was like swimming through molasses - i realize we are supposed to be flying or w/e but it would feel better if the ascent and descent happened more abruptly
pretty decent concept, generally happy and fun, but it needs a lot of work. i'll look forward to the completed version and check out your earlier titles as well. good work.