i don't like the theme either, but so what, i've got a lot of ideas. and i've also chosen one that i both like and can see myself actually doing, so just throwing these ideas out there. feel free to use

• you have limited space in your stomach, but you should not disappoint the hosts who feed you
• basically any game with inventory
• you live in/move in to a tiny apartment and you have to fit your stuff
• you live in a dormitory/hostel
• you're imprisoned so all space you have is your cell
• you give out presents in boxes and you must fit everything
• you're a farmer and have to manage your plants in a limited space
• you're space traveling but found out there's a barrier that confines you
• you're space traveling but you can't navigate very well due to inertia, so as soon as you accelerate, your future space is limited to a narrow cone

if you have your own scraped ideas, feel free to share them as well ^_^