Superpowers assets various 2d
Miscellaneous 2D objects, items, and effects from Sparklin Labs' Superpowers HTML5 game maker.
Superpowers has a variety of free assets: 2D sprites, backgrounds, 3D models, sound effects, music, and animations. These are the effects, items, and objects that don't fit into the other categories of assets: http://opengameart.org/content/superpowers-asset-packs
They make periodic updates to thier asset packs. You can always find the latest version of the full asset pack at https://github.com/sparklinlabs/superpowers-asset-packs