An overall strong entry! I really appreciate how you've used the static screen areas in an interesting way. Not being able to see ahead of you, and having to quickly scan the new screen area while running out of oxygen to hopefully find a new flower is a compelling way of using what was originally a limitation of the hardware.
While I quite enjoyed the game overall, there were two points that detracted a touch. As some other comments have mentioned, the wall-jumping feels a bit awkward and the platforming challenge near the end with the floating blocks ended up being frustrating. And secondly, the SFX that plays when one of your bullets hits a wall is way too loud and feels very grating.
Despite those two points, this was definitely a good jam game, great work!