I think doors being literally doors are good.
About the boss, it could be a giant variation of the eye enemy, what do you think
Hey, so I'm basically done with the game. Title, player and enemy code, some room presets. It's all basically done. What I'm saying is that when you send me anything, I'll have it done in an hour at most. I'll be polishing the game until I can add additional stuff. I am also working on a NPC speech system and a merchant system.