Moderation!
While accessibility of this game is in doubt I will move this topic to general game discussion, (I can always move it back again if the game is made accessible later).
If the game does have tts support the problem seems to be firstly that there is no way of activating it, and secondly that there is no way of interacting with the game itself without clicking on things.
When I start the game, IE after I've hit "play" on the config property sheet, I can hit the left mouse button once to get from the title screen to the first options screen.
I can visually see a list of textual options there and use Ocr to read them with NVDA, but unlike with say a console game, there is no way of interacting with them via the keyboard, you seem to need the mouse to click with.
This might be just an oversight, but I am guessing this means the entire game is mouse based, and the tts option is simply an additional output method for sighted players rather than something specifically access based.
While it wouldn't be hard for the developer to add an accessible way of starting the tts itself, EG shift s on the main menu, if the game is entirely mouse based I'm not sure how easy it would be to add keyboard shortcutts for things.
sadly, just because something is text based, doesn't mean sighted players will forgo their clickerty click mouse based interface rather than, you know having to actually type stuff .
So, while its definitely worth contacting the developer and asking , this might be one of those instances where adding accessibility might be harder than it initially appears, tts or not.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)