Here, do you remember Rom Check Fail? It was a little IP-defying mashup that allowed you to goomba-stomp Asteroids as Mario and stab Space Invaders with Link's sword. Kieron was hugely excited about it at the time. Today I'm excited about Megamash, which takes the concept and rebrands it for the modern flash gaming masses.
Once again picked up by Play This Thing (I really should read it more often), Megamash is a 2D side scrolling platform game about a rabbit who jumps on enemies, until he jumps through a fuzz of on-screen static into another game, whereupon he's transformed into a spaceship, or a bomberman, or a ninja! It's not quite as blatantly infringing as Rom Check Fail was with its appropriation of resources, but Megamash still remains mischievous about it's presentation. That rabbit isn't wearing a red cap and dungarees for nothing.
It's instantly appealing. The levels are designed to let the abilities of one avatar transverse obstacles the previous could not, such as using Bomberman bombs to blow a hole in the previously impenetrable wall. The shots fired by the spaceship framed on a starry outer space background become bouncing Mario fireballs as they pass through the static filter into the colourful Mushroom Kingdom. Enemies change form into the different games' enemies as they pass through the screens, so a Flying Goomba warps into a space invader and back again as it flies out the other end.
A couple of platforming sections can be more difficult than is absolutely needed, but on the whole it's a cutely designed game about applying the different game universes' logic against each other in order to beat the puzzle-like levels. There's also a grappling hook!