What I would like to see is more of an ability to do things with blocks to make them more useful and encourage creativity... sort of like Legos(tm) that can be interacted as part of the platforming environment. Suggested properties might be as follows:
Brick: These sit in the background, stacking at ground-level or on top of another block. You can walk past blocks.
Type A Block: These stack at ground-level (or on another block, but exist dually--you can walk past them on your current level or jump on top of them, acting as platforms. By stacking these, you can effectively make "ladders" that you can jump your way up.
Type AA Block: These sit in the foreground and are completely solid--you can't move through them either by walking or jumping, requiring you to jump on top of them. As with the others, these stack at the ground level or on top of another block. To prevent these from being permanent obstacles, you can use a pick, shovel, or axe to break through them. There could be bonuses based on tool and Mining skill to speed up the process.
Type AAA Block: These can be mounted in mid-air, thanks to the bubbles in them. Otherwise, they act as type AA, above. This allows one to build doorways "stone rainbows" and the like.
To add to the fun, we could also have dye-making, either as part of our various liquid skills or with a special "mixing bowl." The dyes we make could color the various blocks. Effectively, this would let the players participate in making new art within Glitch--something new to do that gives us more ways to pass the time.