No it doesn't, it just has to involve first person and projectile firing.
this is very clearly not going to progress further considering how redundant we're being
You shoot portals and gravity wells until robobitch stops moving, from the first person perspective
except that's not what the whole game is centered about
the game is about solving a plethora of puzzles in first person with your gravity portal well thingy gun. the main focus of the game is to complete the puzzles. once again, a game is categorized into a genre based on what the game is centered on and what the largest part of the game is about
in order for portal to be an fps, the portal gun would have to fire portals that somehow damage things such as GLaDOS or the turrets.
or just give chell a pistol or something
