How could this game filesize is only 12MB while similar Fps game like half life has filesize more than 100MB?

The nintendo 64 used an early version of AI upscaling for its textures. This meant games could fit on cartridges while Sony was stuck with CDs which were more expensive to make at the time. The downside is that the AI algorithms are difficult to emulate which is why even modern N64 emulators have all sorts of graphical glitches.

>>712626895
>CDs
>more expensive than cartridges

>>712626606 (OP)
Why is his mouth so wide?

Audio takes up a ton of space.