For many games the lower limit is 30 FPS for it to feel not like a slideshow. 60 is considered mostly smooth. Up from that it will feel smoother a nice achievable swetspot is 90-120 FPS. Everything above that is only really useful for esports.

It depends on the person and the application.

For most people, when it comes to film, 24 frames a second is the minimum necessary for it to be perceived as fluid motion.

With a video game, where the user controls the input, 30 frames per second is typically the minimum target necessary for fluid motion; but personally, I only see it become truly fluid at 60 or more.

You can certainly see a lot more than that and reality doesn't really operate on frames per second, so there's no way to know how many FPS becomes more than you'd ever perceive.

It depends on the game.

Chess is playable on 1 FPS, Snake and Pong are probably playable at 10-15 fps, most games where you move your character are playable with slowdown around half speed (30 FPS), and slowdown is hardly noticeable on the 50 FPS column unless the game is very time-precise or it's being speedran

I used to play software Quake 1 on a POS Cyrix (remember them?) PR133 x86 clone. 30fps + 200-250ms ping. 30fps felt fine bit the lag was miserable until QW came out.