Fake-08 development trails PICO-8 so it’s possible your Fake-08 version is out of date, the cart is made with a newer PICO-8 version, or the cart is just plain incompatible with Fake-08 (many carts do not work with Fake-08).
I have a couple handhelds like yours and the official raspberry pi PICO-8 build works great on them - I suggest you get a PICO-8 license and check your distribution’s documentation to learn where to place the raspberry pi PICO-8 binary in the filesystem.
Any progress/news re: C# web export?