[Multiplatform] Game Series you just stopped playing. Sonic is the correct answer, by the way.

Definitely the Sonic series for me. I played Sonic, Sonic 2, Sonic 3, and Sonic Chaos all on the Game Gear when I was very young and I must have enjoyed them, eagerly playing through each iteration. As I grew up though, I clearly started to form a preference for Mario and sort of just forgot or lost interest in the speedy nature of the Sonic games. Perhaps it was a couple of issues within the Sonic series, like the startling number of spikes you could run into, only needing one ring to live technically, and how exactly one attacks with Sonic without being hurt. Regardless, I literally forgot about the series for years and when I started to really get into gaming, all the newer Sonic games were pretty crappy, effectively sealing off my interest towards the brand forever.

Jam it back in, in the dark.