Unreleased games

The much anticipated Sega Dreamcast port of Half-Life never made it to market.

Often development on a video game project starts, but never finishes. Some don't make it past the concept stage, while others are nearly completed, having been promoted, priced or dated for release. Over the years, hundreds, if not thousands of games never see the light of day, either morphing into different projects, or scrapped entirely.

Below is every unreleased Sega-related video game currently known to have existed.