Sonic Advance (with voices!) Episode 1

With the Space Colony Ark safely back in orbit around the planet, everyone thought all was well in the world. How wrong they were! Dr. Eggman is still determined to achieve his goal of world domination, once again turning the animals into robot Badniks to help him search for the Chaos Emeralds. With Rouge on a treasure hunt and Knuckles resuming his duties guarding the Master Emerald, it's up to Sonic and his loyal friend Tails to put a stop to Dr. Eggman's plans...

Featuring the official voice talents of:
Ryan Drummond - Sonic the Hedgehog
William Corkery - Miles "Tails" Prower
Deem Bristow - Dr. Ivo Robotnik

There have been several questions as to how you can play with both Sonic and Tails at the same time, so here how to activate the cheat, from the Versus Books guide:
"On the character select screen, highlight Sonic and press Up once. Next highlight Tails and press Down once. Go to Knuckles and press L once. Then Amy and press R once. Finally choose Sonic select him with A button. You'll hear the ring noise meaning you've activated the code."