Hi aero

the font is called Zoinks / CCZoinks if you didnt already know

the artist (yosuke kihara) loves music and he redraws random album covers all the time lol. you can see a lot of it on his insta if you scroll down far enough

i actually own the same one lol. he's a lottery item made to promote the J-T05 j-phone model which had some kero kero king themed wallpapers and games you could download. Only 1,000 plushes were given out and 5,000 people won a clear file instead.
game.watch.impress.co.jp/docs/20010404/kerokero.htm

forgot to mention the uv issues in sky hoop

i also noticed some textures / objects are missing on certain levels due to culling. if youre using the japanese version of the game, you can use marsa's super jump to get out of bounds and load objects you normally cant see

if you wanna rip haunted zone, every version of project 64 comes bundled with cheats. enable the "unlock extras" cheat and you should have darkness and his stage unlocked as well as some extra options in the options menu