I'm not a skater , and I dont know if this has been done by skaters in the past , but you could add a trick to slide the skateboard on one of its sides while stepping on the other one

PS.: Just a suggestion...And btw , I didnt saw anything wrong with your game , except that everything looks a little bright maby tune it up just a little to look darker , it will give more realism.I think.
Keep it up!