Creature AI should use animal perception, not aggro timers — Part 1/4

This is part 1 of a 4-post feedback series about making Subnautica 2 creatures feel more biological and alive. This post focuses on perception, line of sight, sound, and aggro behavior.

One of the biggest things that makes creatures feel alive is not how dangerous they are, but how they perceive the world.

Right now, some Subnautica 2 creatures feel too much like they are using a game system: detect player, chase, bite, keep tracking until an aggro timer ends. This makes them feel less like animals and more like hostile mobs with perfect knowledge.

A more biological system would make perception matter.

For example:

The creature notices the player through sight, sound, movement, light, proximity, or entering its territory. The creature reacts based on species: investigate, warn, flee, circle, stalk, follow, or attack. If the player breaks line of sight behind rocks, terrain, caves, holes, wreckage, or darkness, the creature should not keep perfect knowledge forever. Instead, it should move toward the last known position and search. It could circle the area, listen, look around, check nearby hiding spots, or lose interest depending on species. Some species could be persistent hunters, while others give up quickly if the player stops acting like prey.

This would make hiding and terrain meaningful. It would also make creatures feel like they have senses instead of wallhack.

Different creatures should rely on different senses. Some could be mostly visual. Some could react strongly to fast movement. Some could be sensitive to light. Some could be attracted to sound or tools. Some could be nearly blind but good at detecting vibration. This would make each creature feel different without needing every one to be fully complex.

The important part is that the player should be able to learn the animal’s perception.

A predator that reacts to fast movement teaches the player to move slowly. A territorial animal that reacts to proximity teaches the player to keep distance. A curious animal that follows tools or lights teaches the player to manage equipment. A blind hunter that follows sound teaches the player to be quiet. A creature that loses line of sight teaches the player to use the environment.

This creates fear through understanding, not just damage.

Subnautica is strongest when the ocean feels like a living place. Creatures should not feel like they are running a simple “player detected = attack” script. They should feel like animals using imperfect senses, memory, instinct, curiosity, fear, and survival logic.