Just to prove that the game is good and worth playing. To measure whether the time invested in the game is "worthwhile", one criterion is to see whether the gameplay helps to "realize the theme of the game". Although many games take a lot of time, the time invested by players is not wasted, because these times are essential for a complete game experience. For example, in the "Soul of Darkness" series, although it takes time to fail and suffer again and again, this price can be exchanged for the gradual proficiency of skills, and training skills is only the main purpose of the game. This also explains why people are willing to spend thousands of hours in competitive online games: in complex competitive games, the growth of skills and experience is almost endless, and players can gain experience from each game, which is in line with the theme of "improving skills to beat others", so the time spent in the game is satisfactory enough.