After playing through both Earthworm Jim 1 & 2 on the Genesis back in the day, I picked up this game for the Nintendo 64 hoping for a similarly hilarious experience. The game has a ton of great jokes with the typical shenanigans you would expect from a Jim game. Launching refrigerators into orbit, using your head as a whip, rivers of baked beans, etc.; the comedy is all there.
In the game, Jim has lost his mind after a cow fell on him and you play as his inner-worm-self. You have to collect his marbles to gain access to new levels and bosses which can be found scattered around every stage. The problem comes when you die...don't die! If you die, you have to recollect all the marbles you've already gathered which is really freaking tedious on the later stages. I can't tell you how many times I've put the game away because of one bad jump that cost me 83/100 marbles on the stage. Also, to defeat the boss characters you must collect a set number of marbles which isn't hard to get the hang of but later bosses like Professor Monkey for a Head and Bob the goldfish just make this literally impossible to accomplish.
Overall I rate this game 4/5 stars because it is a good game, as long as you play it conservatively and can laugh at a few cheesy bathroom jokes. The gameplay is really fun whenever you're doing well so I can't give it lower than a four for that reason.