All of the art packs on that site are under creative commons zero, so you can use them for any of your games, commercial or otherwise. You can also use them as bases for your own art or just use them as temporary art to get your game going (this would be really good for some of the forum competitions). It's a really good resource and is always expanding.
Here's a small list of different asset packs on the site.
- Platformer sprites
- UI sprites
- On screen controls
- Space shooter sprites
jk
