Several Microgaming casinos are giving away 1 hour free play online slots bonus when you join the casino. Try before you buy, excellent way to play slots without any investment on your part. The free play slots bonus will begin immediately after you activate it, which can be done from within the casino lobby after you download the software. Online slots is one of the most popular casino games and at the online casinos giving free play slots bonuses you can play over 200 different slots games. Each month the casinos add new slots to keep the excitement up and giving players more choices of games.