SAGE 2024 - Demo Hotel Hysteria!

First impressions:

• It is confusing that you press Z to select a character when the rest of the menus use the mouse buttons
• It would be nice to be specifically told how many enemies to defeat in stage 3 since there is a counter for them, rather than being given vague wording
• There should not be a risk of the player dying immediately upon a stage starting because an enemy spawned from an open door next to them
• Doesn't seem like I'm able to continue after losing all of my lives, as I'm only given a prompt to continue but no way to do so, forcing me to close the game
• There's a feeling of jank in how the game plays in general

This is quite rough. I commend choosing to base your game's design on Hotel Mario, however it appears that you've taken the design, gameplay, and controls wholesale without attempting to make improvements in some key areas. That being said, giving the player an attack and occasionally giving the player other objectives is a nice touch.
Gameplay overall could use some polish with what's already there. For example, Vince doesn't seem to score points upon defeating enemies as I notice my score keeps going into the negatives while I played with him. Kaizo doesn't have this problem as I can score points normally with her. I'm also unsure if it's intentional but attacking allows me to bypass the tall long legged enemies in stage 4 since you are invincible for the duration of the attack, which does trivialize the threat they likely intended to have.
Generally speaking, taking the gameplay of an already existing product is fine, however what would really show off your creativity and understanding would be examining why you think certain things worked and what didn't in the original, and by polishing or improving design or mechanics that you find didn't work through your game. As a few examples, I would suggest using some kind of visual to pair elevators together such as putting shapes or patterns on them, having pipes connecting them, or by laying them out in a more logical way. I would also allow the player to exit them by using one of the movement keys instead of forcing them to press down. Regarding the doors, I would suggest some kind of visual cue to warn a player if an enemy is about to spawn to prevent any cheap deaths, such as the door shaking or the enemy peeking out of the door prior to spawning. Not having the player start the stage next to one would also help.
I think you could have something here if things were spruced up some more. It's certainly one of the more unique projects I've come across.