Hey thanks for playing it! I used unity and got the pixelated look by rendering the camera to an image texture at a low resolution like 640 by 360 (still 16:9 aspect ratio), and then I just used some post processing to get the grain and adjust colors to try and make it look moodier or older haha.
if you want to do a ps1 style super in depth, the ps1 had a thing where it averaged the position of each vertex so it gave it a wobbly effect and the effect could be reproduced in a shader in any engine. I didn't do this for this game but I want to try it in the future!