Gameplay

Core mechanics, enemies, collectibles, and progression.

Core Gameplay Loop

Galaxy Eggbert is a 3D platformer. The player controls Blupi — a small character — through voxel worlds, collecting treasures, picking up keys and power-ups, avoiding enemies and hazard tiles, and reaching the level exit.

1. Select a gamer slot (1, 2, or 3) on the gamer-select screen.
2. Navigate Blupi through the 3D world.
3. Collect all treasures for a bonus life.
4. Collect any keys required to unlock doors (tracked in HUD).
5. Avoid patrol enemies, hazard tiles (Lava, Spike, Crusher), and fall deaths.
6. Reach the level exit (type 7 object) to advance to the next world.
7. After world 5, progression wraps back to world 1.
8. Losing all lives returns to the gamer-select screen; saves reset to 3 lives, world 1.

Player Character (Blupi)

Implemented in src/GalaxyEggbert/Game/Blupi.hpp and Blupi.cpp.

Physics Constants

Animation States

Animation frames are looked up from Tables::GetBlupiIcon(action, scaledPhase), which maps to the blupi.png sprite sheet (600×2040 px, 60×60 tiles, 10 columns × 34 rows). The animation ticks at 1/3 game-tick rate to match the original 20 fps timing.

Respawn Invincibility

After any respawn (fall death, tile hazard, or enemy hit), Blupi has 2 seconds of invincibility. During this time the sprite flashes (visible/invisible every 0.1 s). Tile hazards and enemy hits are skipped while the timer is active.

Lives and Death

• Start with 3 lives. Maximum is 9 lives.
• Lose a life on: fall death, hazard tile contact, enemy contact (without shield).
• Earn an extra life when all treasures in a level are collected (once per level).
• At 0 lives: game over → gamer-select screen; save resets to 3 lives, world 1.

Collectibles

Hazards

Tile Hazards

Tile hazard detection is performed in GalaxyEggbertGame::UpdatePlay() each frame when Blupi is on the ground and neither the shield nor respawn invincibility is active.

Fall Death

Falling below Y = −10 world units triggers a death. The spawn point is fixed to the position encoded in the level file's blupiPos= header field.

Enemies

All patrol enemies use linear movement between posStart and posEnd. If a patrol enemy's start equals its end (stationary in level file), a default ±2 tile X patrol range is applied. Contact detection uses a 0.85 unit radius check.

Moving Platforms

ObjectType1 is a moving platform lift. It moves linearly between two endpoints. When Blupi is within 0.85 units horizontally and 1.5 units vertically of the platform center, the platform's XZ movement delta is applied to Blupi's position via Blupi::ApplyExternalDelta().

The Level Exit

ObjectType7 is the level exit goal marker. When Blupi's position is within 0.85 units of the exit, Decor::WasExitReached() returns true, the win sound plays, and the game transitions to the Win phase, then loads the next world.

World Progression

• Worlds are numbered 1–5.
• Per-world sky: Grassland (1), Forest (2), Ice Caves (3), Lava Fields (4), Space Station (5).
• After world 5, wraps to world 1 (currentWorld_ resets to 1).
• Each world adds +1 Crusher tile and +1 patrol enemy for increasing difficulty.
• Progress (current world, lives) is saved after every win/loss/quit.

Game Phases (Screens)