When a creature on the battlefield gains a +1/+1 counter, the counters "waterfall" out of view, and the UI breaks in multiple ways. All cast cards from either player stay in the Stack, or attach themselves to the edge of the UI. It can then be difficult to determine which creatures are on the battlefield due to being stuck in the Stack or generally "out of play". When Lands are played, they become stuck on the screen in odd places, covering a large part of the battlefield.