The Halloween mini-game can be activated from the main menu. In it, you can press 'o' to try the spherical variants of the usual lands of HyperRogue. You can also try elliptic geometry, which is obtained from the sphere by considering the antipodes to be the same point -- and there is no real difference between Mirror Images and Mimics in this geometry :) In general, HyperRogue now lets you compare the hyperbolic phenomenons to their spherical counterparts. After Halloween, the spherical/elliptic geometry and the Halloween mini-game will be available in the "Euclidean/elliptic mode" in the special modes menu.
Other changes include:
- Major overhaul of the user interface. Most of this has been actually done in patch 9.0i. The new menus should look better, and adjust to the screen size better (especially mobile). The color dialog has been improved, and it is now used when you edit the colors of your character. Most numerical options are replaced with subdialogs when you can enter the numbers directly, or adjust them with arrows or sliders; and some help is provided for some of the less clear numbers. In 9.1, additionally pressing F5 or F10 while in good game won't stop immediately (ESC screen will be shown first).
- Improvements to the Prince(ss) quest. Some bugs were fixed (jealousy did not work, monsters tended to just stay in place after hitting the Princess -- now they ignore her while she is stunned, and also the stun time is extended). If you have saved the Princess successfully, but she dies later, you can revive her with Orb of Love after you collect 20 $$$ more.
- Orb power is now drained after the monsters move, not immediately after the movement (so Shielding at 1 charge will still defend you for the next turn, and Aether at 1 charge will let you move once more) -- this should be much more intuitive, especially with Orb of Time. Also fixed some bugs with Orb of Time (Thorns or Aether were considered to be used even though they were not). Also fixed Ghosts and Rock Snakes, who did not work correctly with Orb of the Shell/hardcore mode.
- Knights of Camelot now quote Euclid, Lobachevsky, Gauss, and Escher.
- As a reference to Deadly Rooms of Death, Goblins are now afraid of energy swords, and won't step on cells adjacent to them.
- You can now change the projection quickly by pressing number keys. This is useful on the sphere, and also if you want to see the different models of hyperbolic plane quickly. 1 (orthographic or Gans model), 2, 3 (stereographic or Poincaré), 4 (gnomonic or Klein).