Hey Lex! Great clone! I love the fact that you got the game running on a grid system. It really helps contribute to the feeling of the 1980s computer game.
I do wish you could manipulate the speeds of the rotating/moving objects of the first 4 screens like in the original. While it's not much, it does give a bit of entertainment through those pretty long screens above just moving the cursor around.
That said, the 5th screen was very well done! It worked very well and brought in that feeling that was missing from before. Great job overall!