The game is based on the darts pub game around the clock.
You must work your way around the board starting for 1 through to 20; then you must hit the outer bull, then the bull to finish.
Changes:
The bug on the high scores has been fixed. And a couple of enhancements.

AEP-Emu (DE/EN)
DMG Page (DE)
Indie Retro News (EN)
Retroguru (EN)