Very cute game. I think the plant game could be made a bit more challenging by moving the bottom platform along with everything currently stacked on it. You could maybe incrementally make each time you play a minigame harder that way to encourage more alternating between them. i.e. you "level up" the minigame each time you complete it.
For the sandwich game I was waiting around for certain pieces for a while, I actually had that issue with my game too, but I added a percentage chance you'd get a piece of the type you needed before otherwise picking a random piece. Could be helpful here too.
Your onion character was adorable! If you continue this minigame suite after the jam, it'd be fun to see them get some expressions and react to how the player is doing! Great job!