Hello, and thanks for checking in! We are using ren'py as our engine, which has built-in TTS support. It can be enabled and disabled by pressing v on the keyboard. Once enabled, the menus, as well as all the game text, are being read out loud. The menu, as well as the rest of the game, can be navigated exclusively via keyboard, or controller, if that's preferred. Additionally, all of the prologue, as well as all direct speech within the game, are voice acted by the team. Those lines seemlessly are being played while TTS is enabled.
If you have further questions, or improvement suggestions to better help the vision impaired community, please don't hesitate to reach out further.