In the game Cat-Astrophy, each expedition can lead to a different build, thanks to a modular system that allows players to experiment with various combinations of abilities, stats, and systems. This approach creates a unique path to uncover the game's story with each run, even when returning to familiar planets. Players find modules that can modify specific abilities, stats, or systems, and the build takes shape through what they find, keep, and react to in each situation. The modules can evolve and hide synergies that become apparent when combined, changing the way players move, attack, or navigate a room.
The game's combat system also rewards precision and adaptation, with directional attacks that can be customized for forward, upward, and downward strikes. Fatigue builds up as players chain attacks together, forcing them to decide when to keep pushing and when to stop and regain control of the situation. Route selection is also part of the build, with different planets offering unique mechanics, enemies, and rewards. Players can choose their route from the ship that serves as their central hub, and rooms don't follow a single path, allowing for exploration and deviation from the route to look for rewards.