Do customized retro co-op roms work on the actual physic console?

So, i recently hacked my wii u with aroma CWF, and I'm really interested in playing old GC games on it.
As I was scrolling through youtube tho, I saw some videos of people playing with custom roms, making them able to play games such as: Super mario sunshine, both pikmin 1 and 2 or even ocarina of time with 2 players.
So i tried it myself, I injected with UWUVCI AIO some super mario sunshine co-op but it dindn't work.

Well kind of, the game runned until the first cut-scene end, but everytime after that cut-scen it kept crashing.
Does anyone know if i did something wrong?
I also tried another rom, and the game was running fine, but no player was there.

If anyone has accomplished this before, can you please answer with a link to a video on how to do it or a step-by-step guide, that would be so appreciated.