If you are new to online slots or just tired of complicated interfaces, do yourself a favor and check out Black Diamond Slot. I played it on an English casino website that is very user-friendly for beginners. It has adjustable coin sizes, an intuitive paytable, and even a free spins mode to get comfortable with the mechanics. What I like most about it is the combination of simplicity and reward potential - especially with the large and small progressive jackpots.