For research for Oiseau, I did a lot of research into Metroidvania-style games like Metroid (1986) and Castlevania (1986). These games have tightly connected level designs that means players are often retracing steps in order to find an ability, or items needed to open a new area. It encourages players to really explore their world, and to feel a level of control over the puzzles and gameplay. In Oiseau, each skill learned opens a new area of the map that would have been inaccessible without it.