Ecco The Dolphin: Defender Of The Future Sega Dreamcast cheats

Full pause screen
Press Start to pause game play, then press X + Y.

Active map
Hold X (sonar) during game play for a long time. Press X again to return to normal.

Glitch: Swim outside the game world
Encounter the Boss in the "Blades..." level. It is a large room with a Boss that resembles a large dragonfly larvae. Go to the bottom of the room where you can refill you air supply with the bubbles coming out of the ground. Next to the bubbles on the floor near the wall is a small hole. Go through it and get outside the game world.

Dolphin Soccer
This secret is found on the Powers of Levitation level.
To play dolphin soccer against a warring Clan member, the first order of business is to swim to the large central building underwater. Circle it until you find the Information Shard. Enter the central structure here and head down the tunnel until you find an oval door near the bottom. This passage is split up by several organic doors that dilate when you get near them, allowing you to pass. Ignore the side paths for now, just head down the tunnel until you reach the chamber at the end. There is a Clan member here and a bubbler in the center of the room. If you turn and face the entrance, you'll notice an oval section of wall to the left moving slightly in the current. Swim through it to find a secret room. Inside is a Stealth power-up. Grab it and head straight back. There are a pair of yellow lights at the back of the room. Touch your nose to the right one to be taken to Dolphin's World Championship, a soccer match between you and a Clan member.