I never played that but thought "wait, wasn't that originally a 64DD game or a cancelled 64DD game?" - a lot of oddball things(Animal Crossing) spun out of that system. But I was completely wrong.
It made me remember this 64DD game, Doshin the Giant, later ported to Gamecube. Pretty obscure when it comes to people that actually played it back when it came out, partially because it was only released in Japan and Europe(no one imports games from Europe or mods their console to play PAL releases). It was not well received either and it looked like a N64 game. Over the years people have started to check it out I think.
I wouldn't call it a fun game, it's even hard to call it anything. My memory is hazy and the only thing I remember is trying to figure out how to play the game in the way games are usually played(how do I win? what's the min-max strategy?) - I strongly suspect that wasn't the point with Doshin.
Reading Wikipedia just now I learned the designer was the guy behind Aquanaut's Holiday and Tail of the Sun which explains a lot.
Cubivore was decent enough if I remember it right, started on the 64DD and then came out on Gamecube. In the current era it would have been a cheaper downloadable game not a full priced release, it would have suited it better.