Hi.

There are 2 minor bugs in the the vertical speed indicator and the pull up warning. The following lines both use a divisor that's suited for 6 FPS, but is 5x incorrect for 30.

Vertical Speed display, line 280:

Actual:

Expected:

Pull up indicator, line 291:

Actual:

Expected:

Those are the two easy bugs.

The following is more of a feature/realism request and isn't keeping with "looking exactly like the builtin Artificial Horizon", but: If you go by real artificial horizons, there shouldn't be any "backgrund" above the horizon line, and when you go through 90 degrees down, the grid should persist until you're level and upside down. See this example[i.imgur.com] for reference.

Regardless of how you feel about the feature request above, there is a slight display bug where the BG texture isn't fully drawn when you get to 90 degrees nose up/down. See this screenshot[i.imgur.com]

I'm not familiar enough with the sprites API/math to fix the last two, or I'd suggest code as well.