SuperMash has a neat central idea, but the game unfortunately can't quite deliver on it. You and your friends have discovered a strange console that's capable of blending two genres together, and you use it to stock the shelves of a game shop. Silly narrative aside, you select two of six genres, fiddle with settings like length and difficulty, and play the results. While you explore what the different genres offer when spliced together, it's relatively entertaining, but this doesn't last very long.
There's a limited pool of characters, enemies, music, and other assets that the game pulls in depending on which genres you pick. Combined with repetitive objectives -- collect X number of coins, kill enemy Y -- you'll start to see the joins very quickly indeed. There are only so many times you can fire up a mix of, say, platformer and JRPG before it all starts to become very familiar. As you play through these mashes, you unlock Dev Cards, which can be used to further customise new creations, but this does little to deepen the experience.
Not only are the mashes repetitive, they're also very short, shallow, and often just plain bad. Sometimes frustrating, sometimes too easy, sometimes impossible -- the randomised nature of mashing hurts more than it helps. Sadly, the novel concept isn't backed up by the execution required to make it work. While some of the mashes show some fun combinations of genre tropes, the majority of what you'll play in SuperMash is a bit of a mess.