Knowledge associated with energy conservation is important but it may appear difficult and monotonous to students due to the presence of jargon and complex scientific concepts. This research created two digital question-and-answer games and compared them with a traditional paper-and-pencil learning method to explore how different learning approaches would affect college students' learning for knowledge of energy conservation. This research conducted a between-subject experiment with random assignment to examine short-term effects of the three different learning methods on motivation, attention, and learning outcomes. The results revealed that participants who played the digital game equipped with more cartoon-style, animated, and interactive features scored significantly higher than the lower-complexity digital game group as well as the traditional paper-and-pencil group on the learning outcome tests. Moreover, in contrast to many previous studies, use of these digital games was not found to affect learning motivation and attention.