Playing around with the graphics a bit, I changed the little character (who TANS still insists defies definition as anything other than a smiley-face) and the "trail" to green circles, and the main character ended up looking a bit like a worm. I then named him Winston Worm and "WhirlyWorm" (a game-name with which I'm not in love) was born.
Worms are always popular for games, because they don't need much for motivation. Since they've barely got a brain at all, anything they do you can just chalk up to being a worm. If he's a space-ranger or a military character, you've gotta explain WHY he's running endlessly down the screen. A worm, however, can just crawl downwards for the sake of crawling downwards.