So this is pretty much the same idea as the NES mockup ports thread, but for Genesis/Mega Drive. I've found it very interesting in that it is a 16 bit system, but there are still some rather stringent color and palette limitations in place forcing you to really think about your actions to get the most out of it. It really gives you some great insights into what kind of challenges artists had to face. In a nutshell, the system's VDP uses 4 different 16 color palettes which tiles/sprites can be based on, and is based on a 9-bit 512 color palette. For the most part, I have been relying on this palette resource for my edits:
Here's one I made for Street Fighter Alpha 2 a few months ago, based on the SNES port assets (maybe the Genesis could have handled a larger screen estate with wider horizontal resolution and/or less black bars, but I left that as it is).
Basically, the background uses 1 palette, the second palette acts more as a jack of all trades with a grayscale and some primary colors, which here is used both for the foreground lift, UI, and projectiles/effects. Then the character sprites use 1 full palette each. Maybe things could have been optimized differently and both characters could have shared 1 palette somehow, but since fighters are very character-centric visually I thought this would be the better approach.
Here's Super Castlevania IV (did you know that Factor 5 had a proof of concept Genesis port they pitched to Konami?)
Here I made a gradient of shadows, midtones and highlights that could all be partially applicable to the bricks, grass/vines and metal fence. Was very satisfied with how efficient that turned out to be. Simon's palette was recycled for the UI graphics, throwable weapons and candles. The hardest part here was the background layer, which really didn't lend itself well to color quantization. I actually ended up redrawing the sky so that it would work better with less colors.
Yoshi's Island
This game is actually not that intensive in its color use, apart from the sky gradient which I had to dither the hell out of, although I don't think it's that noticeable with the colors I chose. Pretty surprised how well it all turned out.
Alien Vs Predator
This one required more work since the graphics had to be scaled down from their higher res arcade counterparts. Maybe the sprites should have been a bit smaller to accomodate for more of them on the screen, given that this is the type of game where you expect to fight hordes of aliens (At least I also made sure to reduce the length of the alien tails so they don't take that many tiles). Level background is 1 16 color palette. Alien sprites are 8 colors. Made sure the player sprite has the pants, hair and skin share more color slots with eachother. I made sure to leave lots of color headroom for other elements not displayed like items, different enemies and a second player sprite.
Mega Man X2
Out of all the games I've tried "porting", the X series is really the hardest one, which seems surprising at first since it's not a game you'd consider that visually "impressive" at face value, but it makes sense when you really start considering all the logistics. The levels usually have a lot of differently colored elements which is difficult to account for when they transition seamlessly. So I made sure to cover 2 areas of Wheel Gator's stage here so as to not work within a complete vacuum. Most of the level consists of an exterior area with a cityscape background and the green armor shell, and then you have the interior part with blue platforms. I made one palette for the exterior (with some undisplayed colors reserved for the big yellow eye setpiece near the boss entrance), and a second palette for the interiors.
Then as you can see I replaced the player sprite with a custom one made to work better with a lower amount of colors. The original SNES sprite uses 16 colors, but I managed to knock it down to 12, even with keeping the armor upgrade visuals in mind (I gave the skin just a bit more of a yellow tint so that it can double as the gold bands for the armor). Most of the grayscale was quantized into bright blue/cyan, all in all giving it a more saturated look. So that leaves 4 unused colors in the player palette that could be used elsewhere, and combined with any of the non-blue colors that don't change depending on weapons. Just haven't figured out what that could be used for yet.
It's also the same size/occupying the same tiles as the original sprite in case you're wondering, just with different proportions.
The fourth palette would be used for generic objects like enemies, projectiles, explosions, interactable props, etc.
Finally there's the issue with the boss sprites and the colors it needs. I was thinking that colors could be switched out in the fourth palette specifically for the boss encounters, but you shouldn't change things that can still appear in that situation like weapon projectiles and explosions, so it's tricky. For Wheel Gator specifically his sprite actually works with the palette I made for the exterior background assets, but the same probably can't be said for other bosses in the game.
Here's one I made for Street Fighter Alpha 2 a few months ago, based on the SNES port assets (maybe the Genesis could have handled a larger screen estate with wider horizontal resolution and/or less black bars, but I left that as it is).
Basically, the background uses 1 palette, the second palette acts more as a jack of all trades with a grayscale and some primary colors, which here is used both for the foreground lift, UI, and projectiles/effects. Then the character sprites use 1 full palette each. Maybe things could have been optimized differently and both characters could have shared 1 palette somehow, but since fighters are very character-centric visually I thought this would be the better approach.
Here's Super Castlevania IV (did you know that Factor 5 had a proof of concept Genesis port they pitched to Konami?)
Here I made a gradient of shadows, midtones and highlights that could all be partially applicable to the bricks, grass/vines and metal fence. Was very satisfied with how efficient that turned out to be. Simon's palette was recycled for the UI graphics, throwable weapons and candles. The hardest part here was the background layer, which really didn't lend itself well to color quantization. I actually ended up redrawing the sky so that it would work better with less colors.
Yoshi's Island
This game is actually not that intensive in its color use, apart from the sky gradient which I had to dither the hell out of, although I don't think it's that noticeable with the colors I chose. Pretty surprised how well it all turned out.
Alien Vs Predator
This one required more work since the graphics had to be scaled down from their higher res arcade counterparts. Maybe the sprites should have been a bit smaller to accomodate for more of them on the screen, given that this is the type of game where you expect to fight hordes of aliens (At least I also made sure to reduce the length of the alien tails so they don't take that many tiles). Level background is 1 16 color palette. Alien sprites are 8 colors. Made sure the player sprite has the pants, hair and skin share more color slots with eachother. I made sure to leave lots of color headroom for other elements not displayed like items, different enemies and a second player sprite.
Mega Man X2
Out of all the games I've tried "porting", the X series is really the hardest one, which seems surprising at first since it's not a game you'd consider that visually "impressive" at face value, but it makes sense when you really start considering all the logistics. The levels usually have a lot of differently colored elements which is difficult to account for when they transition seamlessly. So I made sure to cover 2 areas of Wheel Gator's stage here so as to not work within a complete vacuum. Most of the level consists of an exterior area with a cityscape background and the green armor shell, and then you have the interior part with blue platforms. I made one palette for the exterior (with some undisplayed colors reserved for the big yellow eye setpiece near the boss entrance), and a second palette for the interiors.
Then as you can see I replaced the player sprite with a custom one made to work better with a lower amount of colors. The original SNES sprite uses 16 colors, but I managed to knock it down to 12, even with keeping the armor upgrade visuals in mind (I gave the skin just a bit more of a yellow tint so that it can double as the gold bands for the armor). Most of the grayscale was quantized into bright blue/cyan, all in all giving it a more saturated look. So that leaves 4 unused colors in the player palette that could be used elsewhere, and combined with any of the non-blue colors that don't change depending on weapons. Just haven't figured out what that could be used for yet.
It's also the same size/occupying the same tiles as the original sprite in case you're wondering, just with different proportions.
The fourth palette would be used for generic objects like enemies, projectiles, explosions, interactable props, etc.
Finally there's the issue with the boss sprites and the colors it needs. I was thinking that colors could be switched out in the fourth palette specifically for the boss encounters, but you shouldn't change things that can still appear in that situation like weapon projectiles and explosions, so it's tricky. For Wheel Gator specifically his sprite actually works with the palette I made for the exterior background assets, but the same probably can't be said for other bosses in the game.