When clicking on a place you want to go everything works fine but when you hold left click your character will only move towards the bottom of the screen. It seems to happen only a little bit once and awhile at the start but over time it worsens to the point where holding left click will make you go straight down no matter where your cursor is on the screen. It's really annoying that halfway through a level you end up not being able to move with the mouse hold. A relaunch of the game fixes the issue temporarily.