Try installing the APK on your phone and see what bugs you get.
The red-cross-on-checker-squares is the image AppGameKit uses on Android when it can't find/load the image file (windows version outputs a warning and quits, Android version just keeps going and uses the alternate image).
Most likely the error is one of two things then:
1. Can't find the image
2. Can't load the image (ie. corrupted, wrong format, etc).
Possible fixes:
1. Make sure you using the right paths/cases
2. Make sure you're copying the image file into Assets/media/[filename].png (and the subimages.txt file) (unless of course you're loading it from a sub directory)
3. Open the image in your favourite editor, make sure it's RGB mode (not monochrome) and re-export it.
The fact that you got it working on your phone through the AppGameKit Player makes it seem like it's probably no.2
