Sea Urchin

Core Role: Not an enemy but a hazard. The Sea Urchin never chases, never attacks and never dies. It is level geometry that hurts, used to shape safe routes through water and along the shoreline without walling the player in.

🎮 Gameplay Function

• Static threat. It holds its spot and damages anything that touches it. No aggro, no leash, no chase.
• Damage: 1 point, on a cooldown, so brushing past costs one hit rather than draining a bar.
• Route shaping. A cluster of urchins turns an open swim channel into a lane. This is its real job: it is the aquatic equivalent of a spike strip.
• Idle motion. Gentle bobbing and swaying, each urchin offset from its neighbours so a bed of them moves out of sync and reads as alive rather than tiled.
• It hurts on land too. Urchins sit at the shoreline as well as underwater, so Koopa can catch one while walking as easily as while swimming.

🗺️ Placement Guidance

• Beds, not singles. Their purpose is to define a channel; one urchin is barely a threat.
• Never place them where the camera can hide them. A hazard that cannot be seen before it is touched is a fault in the level, not a challenge.
• Pairs naturally with the lagoon channels in Area 1 Level 1 - Sandy Shores - Sunwash Beach: the underwater sections where Koopa swims and Kiko cannot follow.

🔗 Related

• Systems - Interactable and Triggerable: the wider vocabulary of environmental hazards
• Systems - Koopa Abilities and States: swimming