This paper first presents a critical analysis of an existing game (APEX), designed by researchers in psychoacoustics only, to measure psychoacoustic thresholds in preschoolers. Next it presents another game (DIESEL-X), designed by dyslexia researchers and game designers, to remediate the shortcomings of the former game. Via a repeated measures experiment (n = 95), the game experience, attention, and psychoacoustic thresholds are compared. It is shown that the children prefer the game experience of DIESEL-X over APEX. Moreover, the former game was able to measure lower frequency-modulation thresholds than APEX. These results demonstrate that when it comes down to game-based assessment of children’s perceptual capabilities, not all games are equal, and that the quality of game design not only has an effect on game experience, but equally on the scientific measurements obtained via such a game-based assessment.