I just checked out the rest of the site where that semi-old Travis Touchdown skin for TF 2 is hosted, and I found some cool stuff. Turns out the creators of the skin, MechaWare, also makes their own fan games. I've only tried a few of them so far; a Mario-themed 2D L4D tribute, this weird Luigi-focused art game, and the Super Mario/No More Heroes mash-up No More Plumbers. I like them all, but from what I can tell, No More Plumbers has the most to it.
The game utilizes a clever combination of the "videogame languages" from two very different games. Mario's life meter is represented by a super mushroom that pulsates in the same style as Travis's heart-shaped meter from his game. Goombas can be taken out with either the traditional Mario stomp, or a decapitating swing of wrench. Either way, the signature No More Heroes blood-splatter will result; and that's just the start of it. The No More Heroes references are plentiful and fun throughout the 2-part game. There is even a shout-out to Pure White Giant Glastonberry in Episode 2. Very thorough.
Wario plays Thunder Ryu, Peach plays Sylvia, and Kamek does his best impersonation of Dr. Peace. It's all pretty incredible stuff to a No More Heroes fan such as myself. Even if you could give a rat's *ss about NMH, it's still cool to see Mario for the bloody, goomba murdering maniac that he really is. I wonder if the little fat plumber would still have become an international superstar if his games featured gory blood-splatters from day one?