As far as I can tell both space and enter mark a definition card as correct, and skip the showing of the answer. Could we have it so that one of them continues to have this action, but the other has the same effect as 'click to show definition'? E.g. use space to skip through quickly when you're sure you know the answer, and space to check the definition first.
I ask because it's currently quite annoying to switch between mouse and keyboard (or tablet and keyboard) every time it changes between reading, definition and writing mode. I think making it possible to deal with reading and definition mode entirely on the keyboard might alleviate this a bit.