## 4 Discussion
### Game Design Elements  
To answer RQ2, the present study showed correlations between Interest/Enjoyment and seven GDEs, namely, adaptation, challenges, customization, leaderboards, levels, rewards, and theme. This is consistent with previous studies that also demonstrated relationships between these GDEs and enjoyment. However, precise result comparisons cannot be made with our study, given that most previous research assessed individual GDEs or game concepts are too different. Rewards was rated as the best implemented GDE in Tesoros and Anotatlon, and, even when it was not the most preferred, its implementation translated into a significant difference in GDE preference between Agentes and Anotatlon. Further, for Tesoros, rewards showed a high level of Interest/Enjoyment. A possible explanation for these results might be that the implementation of rewards is similar for Anotatlon and Tesoros, but not for Agentes. For Agentes, the rewards consist of points that eventually become badges. In contrast, in Tesoros and Anotatlon, the rewards are coins that players can use to buy items, e.g., unlock new categories or power-ups (i.e., jumps and shields) that help them to continue playing. In that regard, participants mentioned 'the second [Anotatlon] seems better to me with a little more entertainment, better rewards which you can use in the same game as the shields. (el segundo [Anotatlon] me parece mejor con un poco mas de entreteminiento, mejores recompensas las cuales puedes usar en el mismo juego com los escudos. ), P3772'. The results on the use of points in Agentes are thus consistent with those from previous studies, which suggests that rather than simply using a scoring system, designers should contextualize this reward to the main purpose of the game, helping to connect and better motivate players in the game [22]. Our findings are also in line with the observations by [PERSON] et al. [23], who showed that a higher number and diversity of rewards (as in _Tesoros_ and _Anotatlon_) lead to more enjoyment. Participants consistently rated challenges as the preferred GDE for the three games. A correlation between Interest/Enjoyment and the preference of this GDE was not observed, but a correlation between Interest/Enjoyment and its implementation for the three games was found. The qualitative analysis also corroborated these quantitative results, as participants stated that challenges made the game more enjoyable and motivating, e.g., _'It has obstacles and that makes it more fun. (Tiene obstaculos y eso lo hace mas divertido), P2274'_, and _'\(\cdots\)' there is a challenge and it is more dynamic (\(\cdots\)'_) may un reto y es mds dinamico), P3015'_. Additionally, _Tesoros_ and _Anotatlon_ presented a higher correlation value between challenges and Interest/Enjoyment compared to _Agentes_, which might be explained by the fact that there were more challenging elements that the players could encounter, such as complete the race or perform perfect rounds. These results align with [24], who indicated that optimal levels of challenges result in better values of competence and flow. In contrast, in _Agentes_, the goal of obtaining more than 100 points to be validated as a human agent seemed easy, so it did not represent a challenge for the participants. Adaptation was also rated as one of the preferred GDEs. The reason for this may be the inherent variability of the sentences that were presented throughout the games, leading participants to believe that all three games adapt their difficulty to the player as they play. However, this GDE was only implemented explicitly in _Tesoros_ based on player performance, which led to higher values of Interest/Enjoyment in _Tesoros_ and a positive correlation between adaptation and Interest/Enjoyment. These results are consistent with findings from [25; 26], who observed increased flow state and scores when playing a game that adapted to players' performance. Other GDEs that had a particular effect on the game concept preference were the avatar and storyline.