When the game quits the launcher deletes the natives it can find. However when the launcher closes before the game quits, it can't delete any natives.

In the launcher log i says:

---- YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----
---- YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----
---- YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----
---- (We'll do this automatically later ;D) ----

however doing this causes the natives to be unable to remove (themselves).