There interesting, but they don't feel like they would fit into Blockland unless you used nothing but those.
I like they way you did the transparent pieces to the bricks, I just wish they fit the style. They would be useful for foliage.
The idea is to have a terrain generate around you made up of these bricks, and then using plornts chunk generator, bricks that you walk away from are saved to a file, and deleted, when you come back, they are reloaded from that file again, you would be able to break the bricks (each one having a delay, and some requiring better tools) and it would give them to you, a grid system, and you got a pretty good setup for an infinite RPG