Koopa: Abilities and States
High-Level Overview: Koopa is the ground-and-water character. Every one of his verbs is about mass: force applied downward or forward through a heavy shell. He is the only character who can go underwater, the only one who can carry objects, and the only one who can move another character. His moveset is deliberately short on options and long on consequence; each move commits.
Controls
| Action | Button | On ground | In air | Underwater |
|---|---|---|---|---|
| Jump | A | Jump | - | Breach the surface |
| Spin | X | Spin attack | Air spin | Torpedo dash |
| Shell | B | Roll (held) | Slam | - |
| Bubble | Right Trigger | Fire bubble | Fire bubble | Fire bubble |
| Grab | - | Pick up / Throw | - | - |
| Swim Up / Down | - | - | - | Vertical control |
Koopa's bubble and Kiko's tornado are both on the Right Trigger. The duo's two ranged, enemy-controlling abilities sit under the same finger on both pads: deliberate symmetry, and worth preserving in any rebinding.
Core Abilities
Spin
Fires on press. The signature move and the one with the most hidden depth.
- Auto-aim is bubbles only. With a bubbled enemy in range, the press launches a homing dash at it: seek and pop, in one action. Into a normal enemy it is a plain, stick-following spin that knocks enemies back, with no homing pull. No aim button, no reticle.
- Spin → Roll handoff. If B is still held when the spin timer runs out, the spin flows straight into a Roll and hands over its speed. This is the main way to cover ground fast.
- Air spin is one press, no wind-up. Holding the stick homes onto a target; no stick spins in place with no drift.
- Supporting mechanics: pinball chaining between targets, spin parry, and spin-through.
There is no downward drill out of the air spin. The ground pound is a separate input and remains available mid-spin, which covers the same intent without giving the spin a second, competing meaning.
Roll (held B on the ground)
Koopa balls up and slides along a heading the player steers with the stick.
- Momentum is scalar and terrain-driven. It launches off run speed plus a boost, builds while pointed downhill, and bleeds off through friction on the flat.
- It is a spent burst, not a cruise: a launched roll outruns a walk for several seconds, then runs out and settles.
- The roll animation visibly spins slower as momentum drops, so speed is readable without a UI.
- At speed it plows through enemies, damaging and hard-knocking them aside.
- At speed it skips across water instead of sinking.
- Taking a hit drops the roll, so nothing gets stuck mid-roll.
Slam (B in the air)
Three phases: a brief startup hang, a drop under heavy slam gravity, and, if it lands in water, a plunge. Landing rebounds into a Slam Bounce; landing on a bounce pad triggers the high-power Big Bounce.
Slam has separate solo and duo tuning, and mirrors Kiko's matching animation when carrying a passenger.
Bubble (Right Trigger)
- Fires on press, with light auto-aim resolved at fire time: with a capturable enemy in a front cone, the bubble homes; otherwise it fires straight. You aim by facing. No aim button, no reticle.
- On the ground and in water it plays the headbutt animation and fires on the attack frame. In the air it launches immediately; the Right Trigger isn't shared with the slam, so it is free to fire airborne.
- Works while carrying Kiko.
- A bubbled enemy is a spin target (see above) and a bubbled Kiko is helpless; see Systems - Kiko Abilities and States.
Torpedo (X underwater)
A dash with light auto-aim: with a killable enemy in range and cone it rockets straight at it, ignoring the stick until it arrives, then hands control back. Otherwise a plain steered dash. A torpedo that reaches the surface breaches into a Swim Jump.
Carry and Throw
Pick up → Carry → Throw. Both the pick-up and the throw are brief movement-locked animations. The throw launches along Koopa's facing with an upward arc.
Carrying is the ability Systems - Elder Trials gates: Carrying Heavy Objects is a mandatory-trial reward, so the basic carry is available from the start and the heavy carry is earned.
Swimming
Koopa is the only character who goes underwater. The swim root handles vertical control with buoyancy and damping, horizontal movement that coasts and glides when input is released, an entry splash, and a periodic bubble VFX loop. Leaving the water on the ground returns to Grounded; launching out of the surface goes to Swim Jump.
Duo States
| State | What happens |
|---|---|
| Carrying Kiko | Koopa moves and jumps normally; locomotion switches to passenger tuning. |
| Duo Glide | Kiko pilots. Entered immediately when Kiko's A jumps the pair up; the glide starts from the jump, not the apex. Koopa's stick is deliberately cut out; the Seagull steers, and it borrows the Seagull's camera. |
| Duo Slam | The airborne slam with duo tuning, mirrored on both characters. |
| Spin Launch | Koopa's spin while docked fires Kiko upward; see Systems - Kiko Abilities and States. |
| Tornadoed | Kiko's tornado can sweep Koopa out of any land state. He has no controls: the funnel puppets him through the ground-pull and rise phases, then flings him. |
Polish Details
- Idle breaks. After a random quiet stretch, one of three flourishes plays, never the same one twice in a row, and never while carrying Kiko, since the duo pose owns that tree.
- Landing flourish on arriving from the air.
- Short hops: releasing jump early cuts the rise.
- Damage flinch, hit flash, camera impulse and rumble on taking a hit.
Tuning
Each move keeps its own tuning set (jump, spin, slam, torpedo, bubble and locomotion) so a designer can retune one verb without disturbing the others.
Situational profiles are selected automatically: solo versus carrying a passenger, torpedo-jump versus swim-jump. The same move can feel correctly different in the duo without becoming a second move.
Related
- Character - Koopa: personality and relationships
- Systems - Kiko Abilities and States: the other half of every duo move
- Systems - Interactable and Triggerable: spin, roll and torpedo drive Impact Buttons; Koopa's weight drives Rising Pillars
- Systems - Enemy AI Framework: how enemies respond to each of these