In this article we critique the use of traditional standardized tests for the cognitive assessment of children with neurodevelopmental disorders. Limitations stem from the lack of integrating (a) results from research into the psychological functioning of these populations, and (b) the main arguments underlying models of human development. We identify four secondary issues in this discussion: (1) these instruments cannot be used with children who have particularly low cognitive functioning; (2) little or no variance in the scores obtained by individuals with neurodevelopmental disorders, because all are at floor, prevent adequate interpretations; (3) measurements do not provide information useful for the design of intervention strategies; and (4) different cognitive and/or neural processes may underlie behavioural scores 'in the normal range'. Rethinking traditional assessment methods in favour of technologically-mediated games yields new cognitive assessment possibilities.