GAME 1303 — Tier 3: Movement Add-ons & Signature Mechanics

Eighteen scripts that bolt onto the Tier 1 player. Most are true drop-ins: add the component, done. Three Tier 1 files get a small v1.1 update (in Tier1_Updates/ — replace the originals):

PlayerController2D v1.1 — adds MovementLocked, SpeedMultiplier, CanCoyoteJump, ForceJump(), ClearJumpBuffer(), JumpHeld, MoveVector, Facing, FaceDirection(), BaseGravity. Behaviour is otherwise identical.
Health v1.1 — adds SetInvulnerable(seconds), ClearInvulnerability(), SetMaxHealth(), SetCurrentHealth().
DamageOnContact v1.1 — now respects its enabled checkbox (Unity sends collision messages to disabled components; this fixes that so MetalObject can toggle it).

Scripts/
  Movement/  Dash, DoubleJump, Glide, Sprint, WallSlideJump, Ladder + LadderClimber,
             MomentumLauncher, GrapplingHook
  Balloon/   BalloonController, FuelSystem, FuelPickup, WindZone2D
  Special/   MagnetPull + MetalObject, RailRide + Rail, CharacterDefinition + CharacterSwapper
Tier1_Updates/  PlayerController2D, Health, DamageOnContact  (v1.1)

How the modules cooperate (worth explaining once)

PlayerInput in Send Messages mode calls OnJump, OnMove, OnAttack... on every component on the player. So DoubleJump, WallSlideJump, LadderClimber, RailRide and GrapplingHook all hear the Jump press and decide among themselves who acts: the controller if grounded/coyote, otherwise wall jump > ladder jump > double jump. While a module owns the body (dash, wall-jump lock, ladder, rail, rope) it sets controller.MovementLocked = true so the base controller stops writing velocity, and clears it when done. Anything that grants temporary i-frames goes through Health.SetInvulnerable.

Input actions to add (Input Actions asset → Player map)

Action	Type	Suggested bindings	Used by
`Dash`	Button	Left Shift, gamepad B/East	Dash (or tick Use Sprint Action)
`Grapple`	Button	Right Mouse, gamepad LT	GrapplingHook
`Magnet`	Button	Right Mouse, gamepad LT	MagnetPull
`Character1`…`Character4`	Button	1–4 keys	CharacterSwapper (optional; Q/E `Previous`/`Next` already exist)

Everything else uses the default Move, Jump, Attack, Sprint, Previous, Next.

Per-game quick recipes

Apep's Trial (2D mode) — Dash, DoubleJump, Glide, Sprint. All four coexist without configuration.
Zap Attack — Dash (Invulnerable ✓, plus a child Hitbox toggled by OnDashStarted/Ended for dash-through), WallSlideJump, RailRide + power-line Rail objects.
Stardust — Dash, WallSlideJump (+ Tier 2 MeleeAttack/ComboCounter).
Spark of Corruption — CharacterSwapper with four CharacterDefinitions; abilities per character: Fire Aprice → MeleeAttack, Dash; Servant → GrapplingHook, DoubleJump; Archer → ProjectileShooter, WallSlideJump; Sorcerer → ProjectileShooter, Glide. Shared health off or on — designer's call.
Roach Invasion — CharacterSwapper, Separate Health Per Character ✓ (5/3/2/3 HP per insect), abilities: bee → Glide + DoubleJump; others → LadderClimber, Dash, etc. Wire Health.OnDied → CharacterSwapper.OnCurrentCharacterDied instead of RespawnManager.OnPlayerDied, and RespawnManager.OnRespawned → CharacterSwapper.ReviveAll.
Missile Man — Sprint + MomentumLauncher (with a disabled child Hitbox, big knockback). Set Tier 2 MeleeAttack off or don't add it.
Hot Air — no PlayerController2D. BalloonController + FuelSystem + GrapplingHook (Aim = Mouse) + Health + Tier 1 Checkpoint/RespawnManager. Wire RespawnManager.OnRespawned → BalloonController.ResetMotion and FuelSystem.RefillFull. Scatter FuelPickups and WindZone2Ds (rotate to aim).
The Magnet — MagnetPull with a HoldPoint child; metal props on a Metal layer with MetalObject + a disabled DamageOnContact (Target Tag Enemy). Enemy weapons/shields as separate metal rigidbodies attached with a joint the player can break by pulling — an advanced follow-up.
Detective Liz — LadderClimber for floor changes (or Tier 6 FloorTransition later).

Animator parameters these scripts use (all optional — they check first)

Triggers: Dash, DoubleJump, Launch. Bools: IsGliding, IsWallSliding, IsClimbing, IsRiding. Float: ClimbSpeed.

AudioManager names referenced

dash, jump, launch, magnet, throw, rail_on, collect.

Notes for the instructor

CharacterSwapper deliberately uses one player object with all ability components present and toggles enabled per character; it avoids the camera/PlayerInput/RespawnManager churn of swapping prefabs. CharacterDefinition.enabledAbilities is a list of component class names — typos silently disable the ability, so a quick check in class is worthwhile.
GrapplingHook creates its own DistanceJoint2D at runtime; students shouldn't add one manually.
RailRide walks the EdgeCollider2D polyline segment by segment, so wires can have any number of bends.
FindFirstObjectByType (CharacterSwapper) is Unity 2023+/6; on 2022 change to FindObjectOfType.
Same caveat: hand-reviewed, not compiled here. Tier 3 has more interacting parts than 1–2, so an import-and-play pass matters more this time — especially the Jump ownership chain.