So I played a good deal of Golvellius and Phantasy Star. Goddamn, some of the early Master System games have gameplay that rivaled late, polished NES games.
I didn't realize that Golvellius switched gameplay styles like that. I thought it was all top-down Zelda style. It's like a cross between Zelda 1, Zelda 2, shooters, and maybe Castlevania. I played through a few sidescrolling parts, made it to the overworld, killed some things, then opened up some holes in the ground to meet lots of people that I saw in Trufun's Golvellius 3D videos. Some of the holes force the screen to scroll for you, it looks like. There are lots of different gameplay styles going on. I need to sit down and beat it.
Phantasy Star was also impressive as shit. It's like a cross between Dragon Quest and Final Fantasy on the NES. I definitely have to say that it's more polished than both. It could pass as an early SNES RPG or Genesis RPG (it is definitely very close to the sequel).
So anyway... since Kendall and I had to spend a shitload of money at Dragoncon, and I had to drop over a K to get my goddamn Prius fixed, I'm kind of on a budget this week:
Final Fantasy Adventure (GB):

This is another one that I've actually never played... I hear it's supposed to be like a soul predecessor to the Secret of Mana series, so it has always been a "must-beat" for me. I think I'll play it on the trust ol' Super Gameboy on SNES...