Not sure what I hate more, the combo shape battles introduced in the forest, or the game thinking it owns my computer and not allowing me to switch to a different tab or move the mouse out of the window
The shapes during normal fights are one of the main features of the game and are here to stay, I'm afraid! Though there is a lot of balance work left to do, for sure.
Does alt+tab not work for you? I just tested it and I have control over everything after tabbing out of the game. If you have more info on this bug, I might be able to fix ^^