What playstation game is this?

I remember playing an old playstation game (on a demo disc if I recall) where you had a small man walking around on top of these giant gray blocks.
You could also change the colour of the blocks to blue or to red.
I think the aim of the game was to destroy a certain amount of blocks in a logical way.

My memory of the game is very hazy, but it’s bugging me trying to think of what it is and what it was called. Can anyone help me out?