a couple odd notes about the SMS’s graphics:
The SMS has 16k of VRAM shared between tiles, the background, and sprite data (the color palettes are stored separately). That 16k is enough for 512 tiles with 4 bits per pixel (whereas the NES is 2bpp). However, since the tiles and background share the same memory the effective amount of usable tiles is around ~448.
One neat thing that I noticed Golden Axe Warrior does is that it uses the unseen rows of the background as tile data (which it can get away with since the game doesn’t scroll). The garbage at the bottom of the BG here is the same data as the hero’s sprite at the bottom row of tiles:
The hero’s tiles are updated every frame you move.
(As for the game itself, I just messed around with it enough to say “wow this is fast” and “wow nice variable width font”)
Another thing of note is that the sprite data (i.e. the data for sprite positions and stuff) can technically be used as tiles on the background. Golvellius accidentally does this in one place, where we get this beauty as a cave entrance:
The weird motion and flickering of that tile is just the game’s sprite cycling routine doing its thing.
I like how this machine works.