All downloads listed below are licensed CC Zero, you may use them in personal and commercial projects. Attribution would be nice, but is not required.

Platformer

Base pack
360 sprites
Building pack
100 sprites
Candy pack
95 sprites
Extra pack
165 sprites
Ice pack
100 sprites
Mushroom pack
50 sprites
Request pack
100 sprites

Packs

UI pack
140 sprites
Isometric roads
140 sprites
Onscreen controls
400 sprites
Puzzle pack
80 sprites
Hexagon pack
170 sprites
Platformer bricks
150 sprites
Tappy Plane
80 sprites

Other

Smiley pack
25 sprites
Platformer pixel
900 sprites
Space shooter
300 sprites
Road textures
80 sprites
Medals
30 sprites