paulscottrobson The problem with that would be that if the user moved the cursor above the "good" area - in this case the bottom 1/3 of the screen - then the player object would just stay in that position, not following the cursor sideways-wise. If the user then moved the mouse to the other side of the screen, then back down into the good area, the player would "teleport" to the cursor's position. That could be a game-breaking issue, especially if the player object teleported through an object it's not supposed to touch, basically allowing the user to cheat at the game.
A different way to do it would be to set the player's position to the cursor's position, but clamped to the bottom 1/3 of the screen. This would not make the player able to teleport. Details on the "clamp" expression are found here, under "values" near the bottom of the page: https://www.scirra.com/manual/126/system-expressions