You've taken care of the visual aspect and that is very welcome. I was surprised that a pixel art hero fitted with more polished building blocks. Because they have different palettes and while the hero is violent the world is eye-candi, it feels a bit like SWAT meet Super Mario.
I think that the main strength of your proposal is multimodality. First, because you alter the game. But when the aberration comes, you don't just change the game rules (now it is top-down)m but include two interesting mechanics: weapons can change and different enemies, to the extent that demons split into smaller demons. This all results in a fresher experience, as the player is constantly updated so he cannot get stuck in a single mechanic. Also, you are giving the player agency to move (spatial strategy) and to chose which weapons fit best (offensive strategy). The block that runs to you once you hit the ground was also surprising, didn't allow me to relax because that meant that anything else could happen.
Regarding playability, I just missed two things: a sight in the top-down shooter and some input about how many keys I needed to open the door. It could be a bit more storytelling, but after all this is a game jam and I consider it was best to put your efforts on building, as I said, this multimodal experience ;)