Little Alchemy starts with four elements — water, fire, earth and air — and asks what you can make by combining them. Water plus fire gives steam; earth plus fire gives lava; and from there the tree branches out to 560 items including humans, cities, time and the internet.
There are no levels, no timer and no failure. It's a discovery game, and its pleasure is the moment a combination you guessed on a hunch turns out to be right. Jakub Koziol's original launched in 2010 and has been endlessly imitated since.
560 in the original game, all reachable from the four starting elements: water, fire, earth and air.
Water plus fire gives steam, earth plus fire gives lava, air plus water gives rain, and earth plus water gives mud — those four are the usual first discoveries.
No — there's no timer and no failure state. A wrong combination simply doesn't produce anything.