Thanks for giving me such detailed feedback. It's really helpful.
For the game difficulty, as i feel it's the potential selling point of the game, it's quite hard to lower it more. I do see that the learning curve is not polished. If I have enough resource, It's better to have 2 tutorial levels before current first stage. This game (like other game in series) is expermenting 3d movement, mastering the jump mechanic in air will massively increase player's space to dodge bullet as it's much less dense when in 3D.
For the story, I find a way to keep the workload low, and avoid cutscene, so that i can afford decent amount of storytelling for the game jam. For the punchline, I would like to keep it. IMO, sometimes silly shallow joke can gives the story depth.
I like this submission too. The direction seems getting to somewhere. I may keep expanding this game, probably via next jam