In a recent interview Vikas Joshi explained the importance of making online learning exciting for students:

"Now it is an imperative that e-Learning has to be exciting, interactive, visually appealing and should hold the learner's attention throughout. To achieve this, e-Learning courses should consist of interactive elements such as games, simulations, active videos, puzzles, quizzes and more.

While keeping this in mind, one has to also ensure that the training delivers true learning outcome to help the learner be more effective and perform better. Which means, simply jazzing up e-Learning is not enough. A strong foundation of instructional design is essential to interactivity."

Joshi does point out that games and other "jazz" aren't enough...but, I would argue that games are more likely to detract from the learning environment all together. As an adult learner, I want information presented to me in a clear and compelling way. A well-designed visual layout, carefully composed lessons, and teacher interaction can help. crossword puzzles make me roll my eyes.