Xeno Series Wikiさんのイラストまとめ

Melia wears a swimming cap in the concept art of her swimsuit. It was modelled and put into the game, but no piece of equipment uses it, and it has no alternate colours. It is the only unusable armour piece that also never appears in cutscenes.

A few enemy and collectable spawnpoints in XC1 are placed wrong because a number is positive/negative but it should be the opposite. For example, there's a Cute Brog in Colony 9 just vibing out of bounds to the east. It should be with its fellows on the Cliff Lake shoreline.