Assuming your point is that they’re just of the same genre, and not actually necessarily the same, maybe. It is 3D, which is a rather large difference. However its gameplay is practically identical. You shoot enemies, you go to the next room, shoot them, etc. going through the entire floor to find the exit room. There is also a shop room, where you can buy things to help you with your current run. You can avoid the enemies but killing them’s sensible because you need the drops. There are also bosses on each floor (I think it’s each floor in Paranautical Activity). At the beginning you choose between different characters for different stats. All of what I described is exactly the same in both games.
Yes, the gameplay in most FPSs is very similar, but they differentiate through other things, like gametypes, ranks, customisation etc. But for Paranautical Activity, they’ve managed to make a 3D game out of a 2D game and just lost a lot of good stuff. And don’t say “But this is an FPS” because you shot things in BoI. It was just you played from an aerial viewpoint, not first person.
I edited that last bit out, I’m 100% certain I did. Errrm…Discourse? Why you messin’ with me, man? Just to clarify, my hatred is no fault of Nilesy’s videos, it was simply where I was exposed to the game.