Good game systems do not just teach players what to press. They teach players how the world works. That difference matters because a player who only learns inputs can only follow instructions. A player who understands the model can solve problems the game has not explicitly explained yet. This is where Model Transferability becomes important...
A lot of difficult moments in games are not actually difficult. They are simply unexplained. The player enters a room, touches something they did not know was dangerous, and dies. A hidden sniper fires from outside the frame. A floor collapses without warning. An enemy suddenly becomes immune to the strategy that worked five minutes earlier. The game may technically be challenging the player, but the player is not being tested on understanding. They are being punished for missing information they were never given...
