Sonic and the Secret Rings

http://www.sega.com/gamesite/sonicrings/minigame/

Shadow the Hedgehog

http://www.sega.com/gamesite/shadow/minigame/flash/index.html

Sonic the Hedgehog Chaos Crash

http://www.sega.com/gamesite/sonicnext/minigame/

Sonic Rivals

http://www.sega.com/gamesite/sonicrivals/minigame/

Sonic

http://www.langeneggers.ch/Spiele_a/Sonic/sonic.htm

Sonic Heroes Puzzle

http://www.sega.com/gamesite/sonicheroes/minigame/flash/index.html