... The entire Metroid map, converted to the PICO-8 palette and 8x8px sprites @.@

https://www.uomni.com/img/metroid.pico.edited.png

How many unique sprites is that?

Hmm, not sure. XD
It's a processed image. I didn't build it in p8. I just thought it turned out super cool.

UPDATE: Okay, so I built a tool to extract unique sprites from a screenshot like this. The problem is the mobs aren't all properly aligned to the 8x8 grid, and so they get chopped up improperly and counted as sprites...

But, here it is anyway:

(868 unique sprites)

https://www.uomni.com/img/metroid.sprites.attempt.png

Oh? Super cool. Looks like.. half, maybe, of them are garbage at least, and many can be stored more efficiently as flips.

Suggesting that Metroid could perhaps be ported to PICO-8 :)

A Metroid demake seems very doable. The platforming physics would be childs play compared to modern games. You'd probably have to sacrifice a lot of sprites along the way, both to save sprite memory and to make the map data more compressible.

PS: Metroid doesn't store the whole map as a sprite array. There's another intermediate layer, the "room". Rooms are comprised of sprites. The map is comprised of rooms.

PPS: Bitwise, I bet you could get a good sprite count if you cut the list at things that only appear once or some other low threshold.

Here is my attempt to filter out all the noise from the metroid sprite sheet. I've removed all the monsters/npcs since none of them are grid aligned. Once I get rid of all the palette swaps in this image I'll add in the NPCs.

I've been kind of working on this slowly as well. Mostly, devising ways to handle very large tile maps, and building a platform physics engine (yes, it's been done 10000 times but I wanted to just try on my own). The Metroid display engine is interesting because there is a buffer applied to the character to reduce screen movement. I found an engine on here that does the same thing... (and it's awesome) https://www.lexaloffle.com/bbs/?tid=28793
Then, I started to wonder if it would be cooler to build a procedural world instead of a 1 to 1 copy. On and on it goes...