This is a great demo with lots of potential, I got so determined to master this game that I ended up getting over 10k coins without dying ( I only lost them due to a reset of progress ).
I can agree with xyncht that the enemies could have different walk patterns, and I would also like to mention I found a bug with respawning the boss. If you defeat the boss then respawn him you can fight him as usual, and if you kill him multiple times and respawn him that's fine also, however, when you are fighting him and you die then the boss will have been despawned and you will not be given the option to respawn him, the only solution being to reload the game. Nonetheless, I love the game, and small bugs are to be expected at this stage.
Another interesting thing I noticed was the controls, they weren't the usual "WASD" controls, you used a combination of the arrow keys as well as keys such as "S, Z, and X". While it took me a while to get used to it, it definetely kept the game feeling unique in that aspect.
I'd love to see the game progress and I'm considering helping fund its journey forwards, I hope others see this and consider doing the same.
-HappyMcGiggles