As many of the more recent App Store reviews have pointed out, the current version of Ground Effect does not support native iPad. This isn't because I didn't try increasing the resolution, it was the first thing I did when I bought the original iPad on the first day it was available.
Sadly it turns out that the emulation of OpenGLES1.1 on iPad and iPhone4 is broken in a few ways. The most significant of these for Ground Effect is fog. The quick iPad version ran at a rather pathetic 13 FPS!
Some people suggested I should just turn the fog off and shove out an update but I really didn't like the way the game looked without the subtle fog.
Instead of the easy option I decided to look into converting the whole codebase to run under GLES2.0 on devices that support it (3GS, iPod Touch 3rd gen, iPad, iPhone4, iPod Touch 4th gen and iPad2) while older devices fall back to good old GLES1.1
This update will be released fairly soon but has taken a back seat because of other exciting, distracting projects.
The screenshot above is from the almost finished build, seen here running at 30 FPS on iPhone4 at Retina resolution. Note the new craft, water with specular highlights, water that takes shadows of the landscape and higher resolution landscape textures.
Try to ignore the black trees, lack of fog and the fact that I could have just printed a '2' in the corner of the screen and it doesn't actually prove the game is running 30 FPS (60/2=30) at all.