As dirty as a word as it is, we've even been considering a tutorial level purely to make sure that players understand strafing before letting them loose on the game
If you do this, be sure to also hammer it in that the only way to stop flying forward while jumping is to hold the back key. Letting go of forward does nothing.
Also that you can't touch any controls when you hit springs. I think disabling the controls for half a second after hitting an angled spring would help new players a lot.