What makes a good slot game worth trying?

I’ve been looking for some new online slot games to try in my spare time, but with so many different options available, it can be difficult to decide where to start. I usually enjoy games with clear rules, interesting themes, and features that make each session a little more engaging. I’m not necessarily looking for anything complicated, as I prefer being able to understand the basics quickly and then simply enjoy the gameplay. What do you usually pay attention to when choosing a slot game for casual entertainment?