I had to check on CDB (which brought me to check a forum post) in order to understand what to do. The game should explain itself, players are not expected to browse through an offline manual.
The three colours mechanic can open up to some interesting aspects, but as for now you only have to copy 1:1 a picture on a forum. Personally, that's not entertaining nor challenging at all
Indeed, the instructions should have been ingame.
I just didn't have the knowledge, nor time to aquire it, for how to make a formspec with instructions.
It's definately at the top of my wishlist. :-)
About copying buildings, the first altar is simple and that's kinda intentional. A bit like making your first pick-axe in other games.
Later buildings provide more of a challenge, especialy if you want to figure out an efficient way to build them.
The original idea was to have a progress tracker per player that tells them which building to build next. (with pictures of course)
The first would be the low altitude fireworks, then high altitude, then first altar and so on.
But, I'm sure having more buildings early would be nice. Perhaps some kind of utility buildings like teleporters or something?