The background of the first stage, from Ganbare Goemon: Uchuu Kaizoku Akogingu (lit. The Space Pirate Akogingu). This game is a sequel to Ganbare Goemon 3 and it was peaceful night, until something crashed near the woods that are close by Horohoro Temple. Goemon and Ebisumaru decide to investigate this mysterious fire. The player begin their journey in the city of Hagure, much like its prequel. This title got a massive backlash because of the other playable characters, Goroku e Baban, replacing the series most beloved characters, Sasuke and Yae. While this PS1 game is by no means a masterpiece, it is still a solid Ganbare Goemon entry and I recommend to play it, since there's an english translation available nowadays.
This background had so many colors that I made some small sacrifices. It can fit forest stages.