The soft Tetris pieces are definitely fun to play with and I love the accompanying squishing noises! The music is also a great match.
It can be a little unclear what is considered a line, perhaps having some sort of light on the side of each row that shows how much the game thinks it's been filled could help?
It's neat how the characters move and react to things. Having them be stylistically distinct from the jelly Tetris gives the game an interesting mix of aesthetics, but I think the surrounding machinery could benefit from having some cartoony shading or elements to match the characters.
Making a functional and satisfying game with funny physics in a limited time is quite a hard task. Great job on bringing your wild idea to life!