From Wikipedia supplemented by User Submission
Tiny Toon Adventures: Buster's Bad Dream was the second Tiny Toon Adventures-related game released on the Nintendo Game Boy Advance. It was released on July 5, 2002 in Europe and was developed by Treasure Co. Ltd and published by Swing! Entertainment Media AG.
In 2005, a US version of the game began popping up on eBay and at small retailers, published by Treasure-regular Conspiracy Entertainment as Tiny Toon Adventures: Scary Dreams. Aside from the title screens and legal information, it was virtually unchanged from the European version of the game. According to information on the box, copies of the game appear to have been produced in 2002 and shelved between then and the time it surfaced.
Another game (also developed by Treasure under the supervision of Hitmaker), Astro Boy: Omega Factor, used some gameplay ideas from this game, particularly regarding the way enemies could be knocked into each other.
This is a Beat 'em up game that features the Tiny Toon Characters. Buster Bunny moves from left to right through 4 scrolling worlds, encountering various bad guys that he can assault with 16 unique combos.
The Player can choose an extra sidekick from the Tiny Toon world, enabling more special abilities (power ups, extra strength etc.). These are only active for a short period of time on each level.
At the end of each world a big boss monster must be defeated in a final confrontation. No game saves are available - the game instead uses a password feature to allow the player to continue from where they left off.