I accidentally discovered a new glitch while attempting runs which allows you to fight an enemy, and remove a different object from the board (an enemy, apple, shop, etc. You can even delete the staircase!). I'm calling it the Quantum Entanglement Glitch because I'm a nerd.

To perform: Click on an enemy with the mouse. Before the battle begins, use the controller to run to a different spot. After the battle is over, the object at your new location should be despawned instead of the enemy you fought.

The only restrictions seem to be that you must be able to run quick enough to the object you want to despawn, you can't ignore paths or go through enemies (only swap out one battle for another), and you need a controller and a mouse to perform it (maybe with switch you can use the touchscreen too, I have no way to test it).

This can be used in speedruns to fight a quick battle in place of a longer one, or in casual runs to generate extra experience points (be sure to stand on an empty tile after starting the battle to not despawn anything).

My guess as to why it works is the following: After a battle is over, the enemy needs to be despawned, so the game just deletes the object you are standing at assuming that's the enemy you just fought. I suppose that initiating a battle with the mouse doesn't lock movement with the controller because the movement works differently between the two input methods, and/or they likely didn't expect people to play with both at once.