Rules
Each player takes turns dropping colored tokens into the board.  If a token is not dropped ten seconds after the board settles, it will be dropped automatically.  Get three or more of your color tokens in a sequence to score.   Tokens in a sequence will be eliminated, causing any tokens above them to fall.  Then, two neutral tokens will  drop into the board.  Neutral tokens cannot be eliminated or scored by either player, but can still fall if tokens beneath them are scored.    When the board is full, the player with the most points wins.
Controls
Switch slots with left/right arrow or A/D keys
Drop token with space
Tips
Scoring a sequence can create an opening or sometimes even score a sequence for your opponent.  Make sure to think ahead.
The points earned by scoring a sequence is based on how many tokens are eliminated.  A sequence of 4 will reward 4 points and a sequence of 5, 5 points.
Neutral tokens always drop in pairs in the columns at each end of sequences scored.  For example, a horizontal sequence will always drop them with a space between horizontally, but a vertical sequence will always drop both in the same column.
Completing two sequences with one token will eliminate both, but the previous two tips still apply.  For two sequences of 3, this move would only yield 5 points, but drop 4 neutral tokens.