HyperRogue: A puzzle roguelike in a non-Euclidean world
roguetemple.com
roguetemple.com
Mostly I've managed to make myself slightly ill with my own experiments in rendering motion in hyperbolic space, so I haven't spent too long in HyperRogue.
As long as they cross in front of the eyes. If they cross in the back, the math works, but the brain is not trained for it.
In spherical geometry that happens -- you see things which are just behind you, but the brain has problems interpreting that.
Simulating binocular vision is not the only approach though -- you can use a perspective where the objects appear at the correct distances, some non-Euclidean VR games do this.
John Lamping invented a file browser based on hyperbolic 2D [1,2].
[1]: https://en.wikipedia.org/wiki/Hyperbolic_tree
[2]: http://www.cs.kent.edu/~jmaletic/cs63903/papers/Lamping96.pd...
EDIT: that might be because they're not hexagons, they're heptagons (https://en.wikipedia.org/wiki/Heptagonal_tiling). Duh...
And algorithms for the procedural generation are indeed quite challenging (as you noticed, you cannot just work on all 10^7000 cells).
Some kids find a set of four dimensional educational toys, and figure them out.
It's a cult classic, perhaps it would be interesting on hyperbolic plane.
It is not clear how to make a hyperbolic pixel-based game because there is no fixed relation between the map and the screen pixels. (This is also why HyperRogue cannot use pixel art.)
Of course, one could still just pick a dense grid and use it instead of the actual pixels.
There is nothing very close to Tunneler, but there is an Asteroids clone mini-game inside HyperRogue, and a "shmup mode" which is real-time and can be played in local coop.