One of my favorite game makers ever is the little Japanese company, Treasure. They started out blowing our minds with games like Gunstar Heroes, then blowing our minds again with hits like Radiant Silvergun and Guardian Heroes, and continue today with hot games like Sin and Punishment 2. They consistently make fun games that push their platforms to the limits. Here is my small tribute with fanart pulled from Pixiv. Sadly, I couldn't find more for Dynamite Headdy.
Here is a cool piece that was released within the Sega Ages 2500: Treasure Box on PS2 in Japan. It is a beautiful and rare piece of official promotion artwork used for Gunstar Heroes.