Little Alchemy 2 rebuilt the original from scratch rather than extending it: 720 items, new artwork, and a crafting tree with real internal logic behind it — combinations follow how things actually relate rather than being arbitrary.
It also adds encyclopaedia entries for every discovery and a hint system for when you've genuinely run out of ideas. It starts, as before, with water, fire, earth and air.
It's a full rebuild rather than an expansion: 720 items instead of 560, new art, encyclopaedia entries for each discovery, and a crafting tree with more consistent internal logic.
720, all reachable from water, fire, earth and air.
Yes — a hint system suggests directions when you've run out of ideas, which the original lacked.