The transparent brain of the larval zebrafish offers unique opportunities for very large-scale calcium imaging of neural activity. Exploiting this, signatures of criticality have recently been reported in whole-brain recordings. However what happens when this is broken down into individual brain regions is less clear. Using 2-photon calcium imaging of ~10,000 neurons in each of 25 larval zebrafish brains we find that criticality signatures show complex patterns of variation between different regions, with some regions scoring well on some metrics and some on other metrics. Furthermore we find that there are strong dependencies of criticality metrics on parameters such as connectivity and cut-offs. These results suggest interesting diversity in neuronal avalanches across different brain regions, and also that caution should be used when selecting parameters, applying heuristics and interpreting results in experimental studies of whole-brain neural criticality.