"Grey Aliens playing some kind of game."
Turn-based sport game for two players.
You have a team of three aliens.
On your turn, a random alien on your team is selected. You have 3+1d6 moves.
Press LEFT and RIGHT to turn and UP to move forward.
Press DOWN to switch to another random alien on your team.
Push the ball into either goal to score a point.
Score 5 points to win.
edit: forgot to mention anywhere; WASD is mapped to same as arrow keys, so you can have one player use WASD other player use arrows, or alternate on the same whatever.
"Make a game based on the title of any talk scheduled for GDC (http://schedule.gdconf.com/)."
Several other people have already done this by now..
It's a gardening game.