What kind of game object? A banana is an object in some games. Does that work?

Sounds like a fun project, but I think you may want quite a bit more specificity in this request. There isn't enough information here for artists to determine if they're even interested or not. See also https://opengameart.org/forumtopic/how-and-when-to-write-a-good-art-request

Here are lots of backgrounds that could work in a skate game.

Here is a skater boy in (approximately) those dimensions: https://opengameart.org/content/stickman-skateboarder

They may not be exactly what you're looking for, but they may work as stand-in graphics so you can get an example demo working in the meantime. :)

Are you making this for actual hardware or just kinda calling back the old palette and tile rules?
Im currently commissioned to make a Game Gear/Master System game. Ive programmed for the Genesis before so I know how to make Sprites for it as well. Either way I can make objects for you easily, however if you already have a palette and sprite size picked out ill need some of that info.

If you want to PM me and show me what you have in mind or what you already have I can make some objects and build a palette. I am not available to do backgrounds, theyre just rather time consuming. I can make objects and possibly a skater boy.

If you are interested in backgrounds too, I can do those but I personally have no idea how to put those in a genesis game.

@jo666 what sort of specifications do you have in mind for that city background?

Also, I'm also doing commissions right now and will have to prioritze them first of  course, so it might take some time for me to get your background started and ready too.