Well, yeah, you could do spin-offs all over the place (without being actual sequals). We could have a Big Daddy game on the Wii (a la Manhunt), some Nazi torture games on the DS (yaaaaay stylus!), a PSP game that nobody will play (unless the stole it from teh internets), and a prequel and a sequel on some next-gen consoles (which will work fine on your X-box [until it asplodes] or will look beautiful [but suffer jaggies] on your PS3).
For sequel ideas, I figured they would just base things on another Rapture. Or, possibly some other facilities. I mean, they got the main character out of there easily enough, and God knows how many splicers could've snuck out. Since we're talking 1950's genetic-engineering tech, there's no telling what kind of mutated crap could've been set loose when your character decided to break everything with rocket launchers and super-powers. The best thing the writers ever did was make sure that you never had a good look at how complete Rapture's destruction was.
For sequel ideas, I figured they would just base things on another Rapture. Or, possibly some other facilities. I mean, they got the main character out of there easily enough, and God knows how many splicers could've snuck out. Since we're talking 1950's genetic-engineering tech, there's no telling what kind of mutated crap could've been set loose when your character decided to break everything with rocket launchers and super-powers. The best thing the writers ever did was make sure that you never had a good look at how complete Rapture's destruction was.