The document provides 6 lessons for learning game development: 1. Ensure the game has a clear, achievable objective tied to the game mechanics. Remove unrelated mechanics. 2. The game environment must change dynamically even when not being played, and penalize players for inaction. 3. Decide how players are scored, what variables scores depend on, what a winning score is, and how scores are computed using a formula from the beginning. Ensure players understand how actions relate to scores.