Is Sonic Adventure on Steam?

No. Sonic Adventure is not distributed on Steam, so there is no Steam Charts or SteamDB player count for it. Its live popularity is tracked here via Twitch viewership instead.

When did Sonic Adventure release?

Sonic Adventure released on December 23, 1998.

Sonic Adventure

Dec 23, 1998PlatformAdventureDreamcastVisual Memory Unit / Visual Memory SystemNintendo GameCubePC (Microsoft Windows)Handheld Electronic LCD

Sonic Adventure — frequently asked questions

Is Sonic Adventure on Steam?: No. Sonic Adventure is not distributed on Steam, so there is no Steam Charts or SteamDB player count for it. Its live popularity is tracked here via Twitch viewership instead.
What platforms is Sonic Adventure on?: Sonic Adventure is available on Dreamcast, Visual Memory Unit / Visual Memory System, Nintendo GameCube, PC (Microsoft Windows), Handheld Electronic LCD.
When did Sonic Adventure release?: Sonic Adventure released on December 23, 1998.

About Sonic Adventure

Sonic Adventure is a 3D platformer video game in the Sonic the Hedgehog series. The player can control six characters from the Sonic universe, each with their own gameplay and point of view of the story. The game is divided up into two types of levels: Action Stages and Adventure Fields. The division of Action Stages and Adventure Fields are a serious departure from all previous Sonic games. Adventure Fields are non-linear game stages that contain very few items, generally designed for puzzle solving, exploration and plot advancement. Action Stages are more speed based and have Rings scattered in them. Sonic Adventure was the top-selling Dreamcast game and received a sequel in 2001, marking the 10th anniversary of the Sonic the Hedgehog series.

Summary via IGDB.

Sonic Adventure on Wikipedia

Sonic Adventure is a 1998 platform game developed by Sonic Team and published by Sega for the Dreamcast. It was the first main Sonic the Hedgehog game to feature 3D gameplay. It follows Sonic the Hedgehog, Miles "Tails" Prower, Knuckles the Echidna, Amy Rose, Big the Cat, and E-102 Gamma in their quests to collect the Chaos Emeralds and stop Doctor Ivo Robotnik from unleashing Chaos, an ancient evil. Controlling one of the six characters—each with their own abilities—players complete levels to progress the story. Sonic Adventure retains many elements from prior Sonic games, such as power-ups and the ring-based health system. Players can play minigames such as racing and interact with Chao, a virtual pet.

Source: Wikipedia (text under CC BY-SA 4.0).