I had the same problem with the arrow keys not working on my laptop. For me, hitting the "break" key fixed the problem. (On my laptop, "break" is Fn+Delete.)
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Thanks so much for offering this game! It was the first video game I ever played, and I was crazy about it as a kid.
I'm amazed at how much of it I remember from back in the day... guess I played it over and over to still know it this well!