I guess I chose the space bar as it is a straightforward choice and easy to hit even when switching hands or fingers.

I'll consider adding a way to change keys though, as it is a valid point.

Travel time of the space bar can indeed affect the game a bit, though I don't think it's too much of an issue in this case as you're just racing the computer  :D

Thanks, glad you enjoyed it. Unfortunately as per end user license agreement section 354 paragraph 14 (that's on page 52 in the fine print) I am not required to provide replacement for keyboards broken during or due to use of my game :D