I've spend 12 hours completing Dynamite Jack. Have I longed for a game like this in years! The nostalgic going-back-in-time feeling of Commodore64, wow that is not something I come across often.
I bought it because I received a 75% off ticket to this game I had never even heard of - but it's worth the full price. Absolutely!
If you are from an age where you used a joystick and looked into a picture tube TV, you WILL miss out if you don't give this game and yourself a chance to do what I did.