The source code I have here gives me 2288 item IDs (probably different game version), and 1074 recipes based on doing a count of Recipe.addRecipe()
. Perfectly doable, but A1200 with fastmem and HD/CF is certainly the minimum. Perhaps, maybe, A500 with fastmem and HD/CF is possible.
Hand made game worlds can be limited to the amount of RAM the user has, or the map can be loaded/saved in compartments of a couple of hundred kb each, where each compartment also has shape definitions. Loading and saving a couple of hundred kb isn't slow, so should be fine, and can be combined with saving player made changes in some efficient format.
And yes, calling the thing Terraria doesn't seem to be a good idea