Doing something real - sprites and sprite-sheets

I started playing with sprites. For testing I downloaded dog from Wolfenstein 3D and some other retro games sprites. I played with the sprite-sheet editor and sprites packer (used to put together individual sprites into a single texture called atlas). In general I just looked around Unity and check how those tools are working.

Examples, which highlight the fact that nice 2D animation does not require too many sprites:

Wolfenstein 3D

Batman Returns 

Castlevania

Here are listed several sprite database pages, which are good sources for inspiration:

• http://www.spriters-resource.com/
• http://retrogamezone.co.uk/
• http://spritedatabase.net/
• http://erantzo.awardspace.com/
• http://www.nesmaps.com/
• http://scrollboss.illmosis.net/mainmenu.php
• http://tsgk.captainn.net/
• http://www.bghq.com/
• http://www.vgmaps.com/