I don't want a platformer

Hi, I want to make one of those games where you can only see the floor (like Undertale or Prospekt Reborn). I just am having trouble with the character moving. Yes, he can move around, but in a weird way. He only goes right left or up, and when he does, he doesn’t stop. Help?

Keyboard(up)=0 velocity

pls put the link to the game in