The premise was completely brilliant to the point where I'm astonished I hadn't noticed anyone doing this before (I don't just mean in the Jam, I mean like in all of game dev, Mario x Tetris is so obvious in hindsight but if there's a game at any scale from tiny indie to AAA that already did this, I missed it!). The production values and level of polish are SHOCKINGLY high, and it really does feel like a perfect fusion of Mario and Tetris with the cute little Ms. Pac-Man ghost following you around and the googly eyed Tetris blocks. While I did like it, the music does grow a bit monotonous after a while and could use more variety.
I wish it had a save function, so I could go back to Level 5 where I got stuck rather than start over from the beginning. I also think it would be more fun if you somehow could/needed to control the blocks and your little guy at the same time, or as a co-op game where one player controls the blocks and the other controls the character. But this is pipe dream thinking on my part. In the realm of the more achievable, I'd prefer a key-press toggle between modes to holding down X and pressing a direction. With the shifting aspect ratio between modes, this feels like it'd make an excellent mobile game.
With 35+ ratings already, I wouldn't have rated this if the dev hadn't rated my game, and I'm glad they did, so I had a reason to check this out. In many ways the most impressive entry I've played yet, and I really don't even like puzzle games or puzzle platformers.