One word to describe the N64 version of this otherwise fun platform adventure: halfassed.
From the moment I began playing this game, from the intro scene to Mission Control, I couldn't help but notice how much fun I wasn't having, mostly, if not entirely, due to taking into consideration how vast a downgrade this was from the original PSX version. From here, you may be thinking that it should be cut a little slack, due to being a port of the original version; issues are bound to surface. But there is absolutely no excuse for this utterly inferior conversion to the Nintendo 64, which feels like a terribly rushed and incomplete project at best.
For anyone who's played both versions of the game, you can vouch for me when I say that you'll audibly notice the differences right away, which leads me to start off with the single most painfully annoying aspect of the game: sound. Simply put, this game is an assault on my ears. Almost every sound imaginable in this game is reduced to watered down mediocrity. For instance, we have the soundtrack. As it's been said before, the Nintendo 64 has poor sound rendering capabilities in comparison to the PlayStation, which means that various changes and remixes have to have been made to comply with its limitations. For instance, the Mission Control theme, nigh-perfect in every endeavor, is missing quite a few sounds and plays at its base. Then there's there's the completely slaughtered rendition of Totally Scrooged (Christmas level), which has had its intro removed entirely and the rest remixed in a noticeably poor manner, removing all appeal it had in the first place (quite a shame, that; it was pretty damn catchy). As if killing the soundtrack weren't bad enough, the sounds themselves have seen some deterioration as well, such as the item collection sound used for collecting gecko paws, bonus coins, and extra lives being nothing but a repetition of the fly coin collection sound many times in succession.
On the technical aspect, most of the graphics are the same, except for them being a little buggy every now and then to the point where moving to certain angles removes all detail from certain items or structures, revealing their basic polygonal structure. It doesn't occur a lot, but this shouldn't happen at all and when it does, it makes the game confusing. For instance there are the barrels on Cutcheese Island (pirate level); it's difficult to tell the regular barrels from the TNT barrels when the label being the only thing distinguishing their appearances is removed due to the developer's sloppy work leaving the graphics bug to run rampant. Some of the icons looks nice and shinier and by "some", I mean "two". It's almost as if they put more time and care into polishing the bonus and hand icons than the entire port itself. Ironic, isn't it?
But this isn't yet the end, my friends. There are some minor, but significant errors in overall design detracting from the gameplay experience as a whole. There is are a number of clipping issues with this game, as I find Gex being able to penetrate a number of surfaces he normally shouldn't, and getting stuck in small areas and crevices on a somewhat regular basis, such as the area between the blue/red-striped half circle platforms on Holy Moses (pyramid level). The collision detection is also much worse, which means good luck defeating Evil Santa, whacking snowboarding elves, and chasing the various frantic fly coin containers.
I could go on and on about why I loathe the changes riddled within the game, but at this point, I feel a summary is appropriate: this is a mediocre port of a good game and only the most hardcore of Gex fans should bother with this travesty. Everyone else, avoid this like the plague and PSX owners of the game shouldn't even acknowledge its existence based off anything but curiosity, as you'll find yourself thinking about just how much you'd rather be playing the much more polished original PlayStation version.