RSRetroArch VS vkBasalt

On the PC version you can add them with Reshade: https://github.com/Matsilagi/RSRetroArch

For CRT shaders on Linux, I'd imagine that Gamescope + vkBasalt (with these shaders) could work. I just discovered it today, but the results have been hit and miss (I've used it for MAME because I don't like its built-in shaders. Regular games like Minetest and Garry's Mod also work, but Minecraft and Freedom Planet don't)

I don't have a CRT, but I play all modern pixel-art games using CRT shaders for ReShade, especially CRT Royale (and a few others). Games like Blasphemous, Astelon, Infernax, Axiom Verge, and Chasm look absolutely fantastic with the default CRT Royale settings expect for interlacing which should be turned off for most LCDs.

To anyone wanting to play this game, do yourself a favor and install some CRT shaders for reshade for this game, the simple scanlines won't do it for this game and it's a quite a drastic change (be sure to put this on fullscreen on a monitor, not through a phone screen)

Here's some shaders for example: https://github.com/Matsilagi/RSRetroArch/

there is vkbasalt for image sharpening. i don't know if it'll provide the image you want, but you can configure it and see if it fits your needs.

There is a alternative for Linux called vkBasalt. I haven't used it myself, yet, so I don't know how well it works. Your distro may have a package for it.

In the meantime, you can Generate a LUT yourself and apply it to games using ReShade or vkBasalt, but it doesn't apply to the system as a whole, takes a bit of work to use with each game, and there are certain games that won't work with it at all (rendering OpenGL games through Zink might help, but there are still gaps in its coverage afaik). All that effort is not for the faint of heart, lol.

The solution: vkBasalt

In the ticket there is also someone suggesting vkBasalt as a replacement.

The easiest way to do this on linux is to use vkbasalt with goverlay.