It currently supports two zoom levels, and another is planned as well. When zoomed in, you can configure the camera to follow any sprite (most often you will want this to be your character).
It also supports two out of the four Game Boy sound channels, so you can plug in your headphones and enjoy.
Only two games are known to work at the moment: Tetris and Link's Awakening. Tetris runs at almost full speed, while Link's Awakening is more at about half speed (but still very playable!)
I uploaded a Youtube video of Link's Awakening for your enjoyment. Beware, the video and sound aren't fully synchronized.
Next on the list for compatibility is the special rendering techniques which are employed by many games.
.
