I remember renting this one or two times back during my tenure at the University of N64. I was sucked in by the platforming, the crazy characters, the multitude of levels, and the witty wisecracks. But over time, the platforming became frustrating, the characters became bland & uninspired, the levels started repeating themselves (particularly the ones I wasn't fond of, like the computer ones), and the wisecracks got to the point where they made me want to gouge out my own eyeballs with a melon baller.
This is one of those games that would have been extremely good had it not been for a small number of powerful shortcomings. The Gexzilla vs. Mecha-Rez fight was the highlight of the game for me, and I was entertained navigating the hub world trying to find hidden levels in obscure areas. At the end of the day, this game is like a large chocolate egg. It looks & tastes absolutely sweet for the first few bites, but before long you come to the realization that inside, it's naught but a hollow shell wrapped in pretty foil.