About
Deck of the Fallen is a solo-developed tower defense game I’ve been building alongside my studies at Epitech since Summer 2024. Developed in Unity (C#), the game blends deck-building mechanics with open-grid tower placement, offering a deep, customizable defense loop in a post-apocalyptic setting.
Over the past year, I’ve continuously iterated, starting with a prototype to test the feasibility of my ideas. What began as a personal experiment has grown into a game with evolving systems, modular design, and its own emerging identity — and I’m proud to have kept it alive throughout my academic year.
📺 Devlog Series: YouTube – CrystobalDev
🎮 Play the game: Itch.io
🧩 Source Code: GitHub
Project Info
- Role: Solo Developer (Game Design, Programming, Visual Systems)
- Duration: Ongoing (1 year)
- Engine: Unity
- Language: C#
- Platform: PC (Windows)
- Tools: ScriptableObjects for cards, enemies, and units
🎮 Introduction
In Deck of the Fallen, the player must survive waves of post-apocalyptic monsters by strategically placing cards on a free-grid battlefield. Unlike most tower defense games, there are no pre-built lanes – enemies forge their own path toward the player’s base, and defenses can be placed anywhere.
The player builds a custom deck before each game, drawing cards, using a mulligan system, and adapting their hand after each wave.
🧠 Between waves, a merchant offers booster packs – players choose one, unlock the cards for the current run, and permanently add them to their collection if new.
🧠 Gameplay Systems
Card Mechanics
- Each card represents a unit, structure, or tactical action
- Types include:
- Resource units (gather food, scraps)
- Combatants and melee attackers
- Building repair units
- Flame turrets, molotov throwers, and barricades
- spawners that generate additional defenders or ressources over time
Economy System
- Food – spawns units
- Scraps – builds structures
- Gold – triggers powerful “stratagems”
Deck Management
- Players build a deck before battle
- Mulligan system at the start (1 free reroll)
- 2 new cards drawn per round to allow for evolving defense strategy
- New cards from the booster marchant
Progression & Star System
- Survive waves with minimal damage to earn stars
- A “Perfect 3 Stars” is awarded when the player takes zero base damage
🪙 Boosters unlock cards for the current run – and if the player hasn’t unlocked the booster yet, they’ll permanently gain access to it for future matches.
🧠 Enemy Archetypes & AI
Each wave introduces unique challenges. Enemies vary in behavior:
- Kamikazes destroy themselves on impact
- Base-focused units head straight for your core
- Saboteurs target buildings and support units
- Hunter-types track down resource gatherers
All enemies are modular and managed via ScriptableObjects, making the system easily expandable.
🎨 Visual Design & Atmosphere
While early versions used placeholder assets, I’ve gradually transitioned toward a hand-crafted post-apocalyptic visual style, including:
- Custom-drawn cards
- New 3D models (gradually replacing temporary ones)
- Atmospheric color grading and VFX
- Themed assets inspired by nuclear ruin and desperation
🧱 Most visuals currently combine free Itch.io assets with my own designs. I’m gradually acquiring or producing replacements to refine the game’s tone.
📚 What I Learned
- How to architect a full-scale Unity game using modular design principles
- Using ScriptableObjects to manage cards, enemies, and units cleanly
- Creating a tight, replayable deck-building game loop
- Designing an intuitive mulligan system and resource economy
- Handling large solo development across time — from prototyping to visual polish
- Listening to player feedback during early playtests to balance gameplay and eliminate bugs
💡 My biggest challenge was working without visuals for a long time, which made the project feel stuck in a prototyping phase. But pushing through led to the creation of a real playable experience — and a unique gameplay loop I’m truly proud of.
🧠 Future Plans
- Add full save system for decks, progression, and card unlocks
- Expand the demo campaign to 5+ levels
- Polish UI and transition fully to hand-crafted assets
- Eventually consider releasing a commercial version or evolving the engine for future projects
📖 Narrative: The “Fallen” are survivors of a nuclear apocalypse, desperately defending themselves against mutated creatures and hostile forces. Each battle is a last stand for humanity’s remnants.