Sega released a game parodying the failure of the Dreamcast console towards the end of its lifespan!

The game, Segagaga, was only released in Japan and is a parody of the unsuccessful Dreamcast console. The player is recruited by Sega in a last effort to defeat the evil DOGMA Company from taking over the console market.

The game features many Sega characters and games. When its director, Tez Okano, presented the idea of the game to the Sega management, it was laughed off as a joke. When he later re-presented it, he was given a developmental budget. Okana created the game in secret.

When he presented it to Sega, the company was already struggling with the Dreamcast's failure. They figured that at this point, the game wouldn't shed negative light on them or do any additional damage, so they released it.

(Source)