Goblin Tetris

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Asymmetric multiplayer Tetris where one player drops pieces while others play as goblins trying to survive. Features custom P2P networking with UDP hole-punching and hand-crafted puzzle levels.

Game Modes

Asymmetric Multiplayer (PvP):

• Host plays Tetris, trying to crush opponents
• Other players control goblins trying to survive
• Goblins can build and destroy structures for defense
• Real-time text chat
• Custom P2P networking with UDP hole-punching for low latency
• No external networking libraries - built from scratch in Java

Goblin Tower (Single-player puzzle mode):

• Progress through hand-crafted challenge levels
• Each level is an intentionally "bad" Tetris board state
• Crush all goblins trapped within complex structures
• Goblins wander and fall dynamically
• Must strategically clear rows to create paths to unreachable enemies
• Camera pans horizontally through tower sections

Classic Tetris:

• Traditional gameplay with modern visual effects
• Real-time leaderboard integration
• AI opponents using genetic algorithms

Technical Features

Networking (Pure Java, no external libraries):

• Custom UDP protocol with NAT traversal via STUN server
• P2P game state synchronization for real-time multiplayer
• Asymmetric game state replication (host authority model)
• Real-time text chat protocol
• ByteBuffer serialization for game objects

AI System:

• Genetic algorithm-based Tetris AI for single-player
• Multithreaded heuristic evaluation
• Basic avoidant Goblin AI

Rendering Engine:

• Custom 2D sprite batching system (targets 240fps)
• Immediate-mode UI implementation
• Dynamic board illumination
• Screen shake and particle effects
• Smooth interpolation/tweening for all movement ('juice')

Audio:

• Custom stereo spatial audio system
• Dedicated high-frequency audio thread for smooth transitions

Architecture

Multithreaded Design:

• Logic/Render thread: Main game loop and sprite batching
• AI Controller thread: Heuristic evaluation and move generation
• Network Listener thread: Non-blocking UDP socket handling
• Audio Manager thread: High-frequency audio control updates

Tech Stack

• Java / Swing
• Custom UDP networking with STUN
• Custom 2D renderer with sprite batching
• Genetic algorithm AI