Here's Spyro 2: Rypto's Rage in glorious ultrawide (as accurate as I could get it to be, at least XD):
Aside from the GTE Widescreen hack implementation done by tapeq, this great emulator needs no other tweak to make this game run like this. It was hard for me to figure out how to add GameShark codes to it, but after I did, I was truly impressed by how well it ran with my "attempt". No overclock needed, full speed 30 FPS, and input lag almost non existent.
Any slowdown on this video is due to recording. Playing like this in an actual 21:9 monitor (I still own a 4:3 CRT XD) should look amazing. Aside from the small pop ins and outs, if correctly scaled, the sharpness and accuracy makes me wonder if it would look this good on real hardware (although there isn't a GTE Widescreen hack available for it as far as I know)... Using a native 240p resolution makes it look even better, but sadly it cannot be reproduced on video. Adding scanlines would just make the image darker...
I recorded this at 1280x480@60 (my refresh rate was actually 120hz, so display lag at least helped with the small FPS dips, or might've XD), no filtering required, since both X and Y axis are multiples of the PSX's native resolution, keeping every pixel that Mednafen (PSX) adores to show as sharp as possible. I cropped the top and bottom overscan, slightly fixed the left side overscan through the ingame's options (that's how accurate this emulator is, even reproducing stupid black bars XD), and upscaled the video to 2856x1080, so it's wider than 21:9 (just due to overscan).
I took screencaps with the overscan in 16:9 (just the cheat codes) and 21:9 (cheat codes and hack) to show that it's correctly scaled:
16:9, 1280x720
21:9 (2.37:1), 1280x540
Full images:
https://imgur.com/a/T4IIa
I was going to take a 4:3 screencap at 1280x960, but I couldn't position Spyro at exactly the same spot, and even if I used save states, it loads the same memory address that had the widescreen codes loaded in it, so it would always load in widescreen 16:9. Maybe the GTE widescreen hack does some real time stuff, so that's why it didn't mess things up when loading a state without it XD.
It also looks great at high resolution and with PGXP, so if my weak CPU allows, I might do another version using PCSXR-PGXP.