FOSS gamedev and creative worlds

Solved!

Water: i made a ice ore inside the water (replacing 99% of them and abm to replace the last)
Dungeons: replacing cobble textures with stone (looks more like caves)
Vacuum: players that is outside a fake air have to use a spacesuit or will be damaged

You would have to do if player is in air then set breath. This would be like drowning.
http://dev.minetest.net/Player

Either that or you could do damage per second which effects the health instead of the breath.

accept it, i made a spacesuit, players without it in the hotbar will lost 8 hp at time.

Set the mapgen parameter 'water_level' to -31000 and disable the dungeons mapgen flag.

solved!
i made a ice ore inside the water (replacing 99% of them and abm to replace the last) and replacing the cobble in Dungeons with stones (looks more like caves)