Playing the game I noticed the game did not mark special numbers: 2222, 4444, 8888!
The game resets at 0x400 (1024).
The speed doubles at each reset: from 1 to 2, or 2 to 4!
I usually get to 2222 pretty in about 20 minutes!
I made it my goal to personally play till 8888!
PLAY-TESTED to 8888! I may see 20000!