Here’s a list of tiddlywikis gaming oriented or featuring interesting interactive features (apologies if there are duplicate):
Games
- chess : use an iframe to play custom js
- Tiddler Grid — drag and drop grid layout : game board in tw (without iframe!)
- Fun and games - TiddlyWiki toolmap - Dynalist
RPG/TTRPG
- Redirecting to Cedar 5e Wiki : intrinsical’s D&D 5e edition
- https://eberron.tiddlyhost.com : A campaign setting for D&D designed for telling fantastical pulp and noir stories - feature a dice roller, progress clock
- https://ttadventuretime.github.io : A ttrpg on adventure time
- https://cairnrpg.tiddlyhost.com : unofficial tiddlywiki port of the Cairn RPG
- 502Lab — Salvando este y otros mundos desde 1996 (mutabit.com)
More on tiddlyhost: Tiddlyhost , Tiddlyhost
Roguelike
- Roguelike (szen.io)
- TiddlyWiki Game Test — To see how much I can do with only the TW5 core (tiddlyspot.com)
Branching stories
- Branching budget
builder(similar to twine): Budget builder — A calculator for making life-changing financial decisions. (tiddlyhost.com).
Interactive learning
- TiddlyMap : mindmap software for tiddlywiki, can also be used as an interactive map for games. Used on https://atlas-disciplines.unige.ch
- https://groktiddlywiki.com/ - cloze, magicSnippet
- Tidme (spaced repetition): feature a cool knowledge graph
- https://crosseye.github.io/TW5-Chemistry - interactive periodic table of elements
- Educational aids - TiddlyWiki toolmap - Dynalist
Drawing & visualizations
- SVG Spider Chart - for displaying characters stats. I made that two years ago, now you can do the trigonometry without plugins
- ECharts : Visualization Library for TW
- Etch-A-Sketch in TW
- TW Whiteboard — Plugin based on Tldraw
- draw.io plugin
- Tools for data visualizations
Blogs
- gavart.ist —
digital garden 
work repository - great use of the echarts plugin - ⦗ℍ𝕪𝕡𝕖𝕣𝔱𝔢𝔵𝔱: h0p3⦘ — (gavart.ist) - lots of ASCII art
Other
- Presentations and slideshows - various tools to create simple slideshow story in TW
- Font Manager (tiddlyhost.com), Palette Manager -- Feature Complete - #14 by telmiger : might be useful for the design part