I downloaded the game via an APK file and thought that might be the issue, but all the APKs had the same problem. I also wondered if it was due to my Galaxy Tab A7 Lite—which isn't exactly new—but I saw others experiencing the same issues while playing on newer devices with the game downloaded from the Play Store. These kinds of graphical glitches are common in PvZ3—which is understandable, given it's a pre-release—but it's particularly bad this time around. Even on devices where the game doesn't crash or break completely, there are similar issues, like the Gargantuar's texture glitching out or the game grid shrinking down to a tiny size. So I think it might be a problem with the game.