Awesome game. You have a pretty solid foundation to work off.
It got me into the zone. I really like Tetris so I think its cool when ppl rift off the idea. The one element I think you need to capture better is the chaos. Like late into a Tetris game its pure insanity. Its like have fun while drowning. Also head to head multiplayer would put this game on the next level.
I get maybe you want to avoid the hardness of Tetris, but in `Swap` you can just immediately destroy a block when it drops down and just play infinitely that way. Obviously I'm not the game's creator so take my suggestion with a grain of salt. But one idea would be blocks can't get consumed unless you have 3 or more touching. It doesn't seem like a perfect solution, but a/ws good job! Very high quality work.