Could you add this to unlock from explosives technology? As it is now, it's available from the start of the game, despite requiring multiple tech-gated materials like steel, red engines, and explosives.
In prototypes/recipes.lua, simply change line 17:
enabled = "true",
to:
enabled = "false",
and add this line:
table.insert(data.raw["technology"]["explosives"].effects, {type = "unlock-recipe",recipe = "water-bomb"})
to the end of the file
