Could be a really fun game, like have upgrades, make shield and brakes actually do something, minimap, an online level editor, make grounds less sticky (Or whatever you would call them), 3/5.
A few suggestions: New modes, Beginning of game a little bit more noob-friendly (Like when you make a game, set min-max level), only be able to open one of the same games (Like not be able to have more than one account on per IP Address), and Full-screen. Other than those few things, 5/5.
 "Gravity Fight"){kind=icon}
 "VortexWars"){kind=icon}
 "You are a... The Sequel"){kind=icon}
 "Lala Zombie"){kind=icon}