The Adventure Game (1980-86)
22 episodes (split over 4 series), approx 26-45 mins each.
I've probably said on more than one occasion during my time on Blogger that it's been 20-30 years since I last saw [whatever the respective post is about] and didn't know if my memories of it were accurate, but never more so has that been applicable than with The Adventure Game.
I hadn't seen it since it originally aired, which is 37+ years ago, at time of writing (i.e., 2023).
In fact, the only parts of it that I could recall prior to watching it recently were a grumbling aspidistra plant on a tall stand, some odd plastic currency, a salamander, and — the part that I remembered most, like it was burned into my brain — the triangle grid pattern that's used to illustrate this post, known as the Vortex.