This is one of the games that I always come back to and I will keep playing it years to come. It very under appreciated.
It was one of the first Playstation 1 games I played, since it came with the demo disc in the box. I played the heck out of that demo but never was lucky enough to get the full game (I was a kid I couldn't get many games). Once I started collecting PSX this was one of the first games I got. I come back to this game 3-5 times year.
If you never played it just imagine you're near the top of a Tetris game when it gets really intense and you need to make the right moves... now convert that into a 3d action adventure game and you have Intelligent Qube.
On top of that the music is amazing.