slide · merge · survive
Slide every tile at once. 1 and 2 make 3, and from there only matching tiles merge. New tiles come in from the edge you slid away from, and your score is the sum of every merge.
Its rules are tuned for short games: most new tiles are 1s, so a run lasts a few dozen moves.
game by magmacrunch media
original concept Threes! by Sirvo (Asher Vollmer, Greg Wohlwend and Jimmy Hinson). An unofficial take, not affiliated with or endorsed by Sirvo.