Has no-one thought of text-to-speech programs or other screen readers? All you need to do is to have all the text in the game accessible to these programs and add in some sort of markers about what is what for them, and leave those non-visual so they won't be in the way of the people who can see.
The mouse bit then... Pointing something towards a point on two axises shouldn't be that impossible. There's a thing called an eco-gun which relies on this. The closer you're aming to bullseye the higher and faster the beeping sound it makes is. The problem, though, is that not all blind people are ever taught to use a mouse, so said group would still have some difficulties.
One of your options for input would be a parser. Blind people can still type, remember. You wouldn't need voice recignition.
The mouse bit then... Pointing something towards a point on two axises shouldn't be that impossible. There's a thing called an eco-gun which relies on this. The closer you're aming to bullseye the higher and faster the beeping sound it makes is. The problem, though, is that not all blind people are ever taught to use a mouse, so said group would still have some difficulties.
One of your options for input would be a parser. Blind people can still type, remember. You wouldn't need voice recignition.