Screen dimensions 15x12 = 5:4 ratio.
Not even Wide screen BOOOO.
Obviously joking, this has however given me a fun idea which I want to credit your good self with and give you first dibs.
A 16:9 game jam, when people hop on to expect this to mean 1920x1080 imagine their faces when they find out its literally 16x9 pixels to make a game :P
If that doesn't get any takers it could always be bumped up to 32x18 or 64x36.
Then create a scene like this one with an area to overlay the borderless wind of the game so it looks much like this scene but square on rather than isometric as that would be easier to program for.
If it had to be at an angle some engines allow 3d projection which would give them an advantage unless strict rules were put in place that 3d projection wasn't allowed? I dunno, would just be fun to see what people could achieve with such a tiny resolution.
Anyway think it over, would be fun and a cool little lowres challenge.