Pressing the "exit" option just crashes the game. The G key doesn't restart the game, you have to click restart with the mouse.

The gameplay wasn't very good: it's hard without any balance. At the top and bottom of the screen, there's less space between the characters and the edge, so given how fast the meteors are you can just die without any warning.
The characters are too fast to keep under control, especially given how small the map is. However, sometimes when you first see a meteor approaching and tell them to move, the time they spend turning around is enough for the meteor to hit them.

Ultimately, the game winds up just being frustating instead of fun or challenging. It'd be nicer if the three character functioned as three lives: you gain a point for each meteor each of them evades, with three surviving a meteor being three points, two being two points, and one being one point. That way, the difficulty would lessen and become more flexible while the player is still encouraged to keep all three alive.