i don't know if it's a know bug, the the game might have memory leak, i tryied it recently, and i'm pretty sure i tried the 1.0 ver too, and this bug was present too
for little sessiosn it's okay, but betwen 3 to 6 characters, or a bunch of clicks, the game start to slow down quite heavily
aside from that, the game is simple but good/enjoyable, hope this issue will be fixed :)