Matching game difficulty to player ability is a crucial step toward a rewarding player experience, yet making difficulty adjustments that are effective yet unobtrusive can be challenging. This paper examines the impact of automatic and player-initiated difficulty adjustment on player experience through two studies. In the first study, 40 participants played the casual game THYFTHYF either in motion-based or sedentary mode, using menu-based, embedded, or automatic difficulty adjustment. In the second study, we created an adapted version of the commercially available game fl0w to allow us to carry out a more focused study of sedentary casual play. Results from both studies demonstrate that the type of difficulty adjustment has an impact on perceived autonomy, but other player experience measures were not affected as expected. Our findings suggest that most players express a preference for manual difficulty choices, but that overall game experience was not notably impacted by automated difficulty adjustments.