Complex sentence: These games require no batteries and all have a wind up start when that happens the game begins and gives you about 24 seconds to play each game has a different goal you need to finish and all are rather challenging.
Split into simpler sentences: These games require no batteries and all have a wind up start when that happens the game begins and gives you about 24 seconds to play. Each game has a different goal you need to finish, and all are rather challenging.