Yep, my first game too, and I remember the song. When I heard the popcorn song many years later in life, I was stopped dead in my tracks because it stirred nearly the oldest memory I had stored in my head.
We had this game but on our IBM PCjr, and something with the hardware config wasn't what the game was expecting which made the sprites scrambled but still in the spot on the screen where they should go. The game was otherwise playable and audio was fine. I didn't see the actual graphics for the game until several years later!
I used to play this a lot. But is it really a dig-dug (1982) clone? It looks closer to Mr. Do! (also 1982) to me.