Meanwhile on most emulators especially pc, Download snes9x archive> extract > Drag and drop Rom to opened snes9x executable> start playing.
Yes I am aware that retroarch is a functional multipurpose emulator for many consoles and it works for many people here, i also understand that it works well and is currently the only one on Wii U, but is a matter of preference. Not many people find retroarch simple even though people who do use them do find it simple.
Only speaking from experience alone, i use it, it works well, emulate lots of consoles, even ones that hasn't been stand alone emulated yet for some consoles as homebrew, I managed to play wonderswan on android using it while no wondeswan emulator exist for android to my knowledge. Even game gear, which i think some exist but aren't free on google store and is great, is a good thing. But the process of setting the stuff up to work is the part i dislike, and i thought the arcade and neo geo emulators like final burn alpha and mame were complex.
Meanwhile the Stand alone emulators on Vwii are simple, open the emulated console desired, select rom and play game, the options are simple to set up and easy to understand and navigate. On PC you can just drag and drop roms to the exe file and instantly load your game, retro arch requires you to first download a emulator core (which is the console you will be playing) that has many to choose from and if you don't know that part well may be confusing, after that, find the directory with the roms in it and scan them. Since the scanning process looks for roms in a universial database that only list official roms and games publised and licensed to display in depht information. Cause of this reason, i really dunno how to play a rom hack on it and end up using a different emulator. Configure drivers, map buttons, some video and audio settings (if is preset a way you dislike) and a few other finishing touches.
It makes for a complete emulation system all in one, once again is good thing but some people just prefer a simple approach and easy to understand. Sadly is the only one on Wii U at the moment (or maybe ever) but is just a matter of preference to some people. If the OP wish to use another emulator, they should try using the VWII homebrew emulators that already exist at this time, and hope they will on WII U in future. Of course it means it doesn't use full power of the wii u system trapped in virtual wii mode limitations, but the gx emulators that are there do work well enough at the time. Honestly i'm glad i can still use them on wii u, cause if v wii didn't exist we would have to had wait until it was possible to even use homebrew, let's remember vwii homebrew was possible From the beginning, as day one i managed to use it with my smash bros game after team boot mii quickly made a homebrew installer for it days after release.