Funnily enough I recently replayed this game, I always love games that let me shapeshift! I'll be honest though, it hasn't aged very well, the game is mixed graphically (it started as a Game cube game I think), it has horrible difficulty spikes, the controls are unintuitive and clunky and the list goes on.
But it was still worth playing through and I do love most of the creatures that Rare created. I would love a more refined sequel (spiritual or otherwise), shame it was cancelled, although a more realistic direction for a planned sequel was misguided at best imho.
I'm now replaying through the brilliant Banjo & Kazooie N&B's, now that is a forgotten and underrated masterpiece! Yeah it has a few problems of it's own, like controls and a camera that are not precise enough, weird and erratic driving physics and some difficulty spikes.
But it's really gorgeous (I'm sad Rare stopped using their own in-house engines), the world's and hub are fantastic (for the most part) and the vehicle creation aspect is true innovation, with endless potential, man does it make me sad we've never had a sequel, too many whiners prevented that...