So it's like Gunpey DS, one save file and no way to clear unlocked content. I guess nobody cared with Gunpey DS since the game sucked anyway.

Weren't there sports games on the Genesis that saved stats and couldn't be erased? I really can't remember because I never played sports games much, I just thought I came across manuals that mentioned something like that. I really don't want to dig through them now to confirm it.