The experiment analyzed reactions of 115 first- to fourth-graders after realizing that they performed worse than they expected in a computer game. Based on the VIOLEX model of expectation violation, we assessed immunization against achievement feedback, assimilation (striving to increase performance), and accommodation (willingness for expectation change). Students decreased their expectations for the next round of the game after getting feedback indicating that they performed worse than expected, and younger students decreased their expectation more than older students did. After giving them some time for thinking about their achievement (and for finding potential excuses for the lower-than-expected performance), younger students slightly increased their expectation, while older students showed a further drop in expectation. Analyses of verbal responses showed that immunizing against the discrepant feedback was followed by an increase in expectations, whereas assimilative and accommodative tendencies did not predict persistence and change in expectations. Conclusions are drawn for future research.