We have discussed this fan created game before in a past post, which I don’t feel like looking up right now, sorry! In short, it’s Mario with Portal guns and yes, it works and yes, it is FUN!
So check out this trailer for Mari0! and download it after that! You can also play multiplayer, design your own map packs and download custom created map packs from their servers! You will be amazed by this trailer!
DOWNLOAD - http://stabyourself.net/mari0/#download