In the create code : hsp=2
STEP
//moving left and right if we can!
if place_free(x+hsp,y){x+=hsp} else {hsp=-hsp}
//colliding with the player.
if instance_exists(obj_player) {if place_meeting(x,y-1,obj_player)&&
obj_player.vspeed > 0 {instance_destroy() with (obj_player){vspeed=-3}} if(place_meeting(x+hsp,y,obj_player)||
place_meeting(x-hsp,y,obj_player)) {with(obj_player){instance_destroy()}}}
//gravity
if place_free(x,y+1){gravity=0.5} else
gravity = 0
COLLISION WITH ThE WALL
if vspeed>0&&!place_free(x,y+vspeed){move_contact(270)} vspeed=0