Nice job. I had a lot of fun playing this one and the difficulty increase at the end felt just right. I'm actually a big fan of the repair mechanic as well so that I didn't have to start all over, but still had to work to continue when I had a mistype in the middle. It was a lot of fun trying to reach Lightspeed!
I did have to look from the word back down to what I had typed to figure out when there was a typo which was frustrating. Some feedback with a noise or red color could be helpful on typos. Potentially even turning the letters in the word different colors as you typed/they moved across the screen so players only need to focus on the words?