A great game that no one gave a chance.
I'll admit right now, even after giving the game more than it's worth of play time, not everyone will like Mischief Makers. It's a game that the people who want to remember the days of blistering their fingers from playing a game so intensely and perseverantly will play long past its expected replay value. The faster you complete the stages, the higher the rank you'll get, the better the time you'll own, and the greater the ending will become. There are many people who will compete with you, like on Mr.Monkeyman's Teasure fan site.
I've put as many hours into this game as I have other premiere N64 titles like Star Fox 64 and Super Smash Bros. Check Mischief Makers out for sure, as it's piss easy to find and shouldn't cost you more than $5. Happy hunting.