[Suggestion] Effect: Sonic

[kolyaventuri]

A bit like #268, I suppose.

On a very short timer, player cannot move but attempting to do so builds up velocity suddenly flinging them on that vector with the cumulative velocity. Much like how in the Sonic games, you can build up speed to progress (GIF).

Alternative ideas:

• Once player lets go of W, it flings them, rather than a timer
• Let player rotate to adjust their vector, but no (relative) forward movement