The intrinsic integration hypothesis proposes that using coregame mechanisms to teach learning material makeseducational games more fun to play and better for learning.Our study tests the intrinsic integration hypothesis with twoeducational versions of Battleship that were designed for thisexperiment, in the domain of complex numbers. We examinethe learning gains and motivation of 58 participants whointeracted with either the intrinsically-integrated orextrinsically-integrated version of the game. Our resultscontradict previous findings supporting the intrinsicintegration hypothesis: participants reported similar levels ofmotivation from both versions of the game and participantswho interacted with the extrinsically-integrated versionlearned significantly more as measured by pretest to posttestgains. This work contributes empirical data to the debateconcerning intrinsic integration, and it highlights the need foradditional studies exploring the integration of learningmaterial into educational games.