Looks awesome. As a fellow retrophile, I can appreciate your idealistic quest. I should be doing other stuff right now, so I'll keep this short.

A) The first Barbarian picture posted, from the main menu, is very nice except for the Barbarian's axe wielding arm. It looks almost like someone took someone's drawing of a Barbarian, and then drew one hand from scratch. The arm looks very short and the angle of the axe (or warhammer?) looks very odd and two-dimensional. I'm also not sure about the anatomy of his chest, it seems a bit out of proportion. It should perhaps be wider on the left side. Right now, it looks like his head is positioned straight above his right pectoral.

The menu with the sword in the background looks great. Maybe you could make the sword more exciting by adding some king of reflection in the blade. Might be too difficult with the limited color palette, I don't know.

Everything else looks great. But is your goal to slowly weed out all the nerds of the human population by burning their retinas with the orange background, leaving them defenseless against attacking stray dogs and crows? If not, I would reconsider the background colour for your sprites.