Don't cross a line. Your head crossing any line's centre, or the wall, ends the run. Your own line counts. Riding alongside or on top of a line is fine, and the last bit of a tail and the bit just behind a head are safe.
Ride lines for speed. Stay close alongside another line. Closer builds speed faster. It drains once you stop.
Overcharge. Riding fills the gold charge bar, faster the closer you ride. When it's full, press Space (or tap) for a burst of speed above the normal limit.
Eat bits. They make you longer, thicker and faster. Thicker lines pick up bits and catch lines from further away.
Cut people off. Dead lines break into big bits.
Head-on, the longer line wins.
New lines blink for 3 seconds and can't be hit.
The arena grows and shrinks with the number of lines in it.
Online is everyone together. 1v1 is first to 3 rounds, against a player or a bot. Bots is offline, with as many bots as you like.
Coins come from length and kills. Spend them on skins in the locker.
Sound
Kenney
All music and sound is CC0, via OpenGameArt and kenney.nl.