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Programming
Game development
Illustration
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About me

Hello there!

I'm an experienced Game Developer and Designer with 4+ years of experience using C#/Unity and C++/Unreal Engine, specializing in optimized UI/UX design. My toolkit also includes Adobe Suite, Figma, and Blender, among others. I've released projects for desktop, Apple and Google Play Stores, and have contributed to diverse game development areas, from crafting engaging 2D player controllers (inspired by classics like Hollow Knight and Celeste) to designing graphics, animations, complex data structures, and real-time multiplayer systems.

Feel free to check my portfolio and see some of the projects I've worked on, a few of which are now published and accessible. I'm dedicated to delivering robust and polished outputs, overcoming challenges to ensure projects reach completion. This commitment includes thorough debugging and testing to achieve high-quality results.

Got an idea or just want to chat about game development? Be sure to drop me a message. Cheers!

iPad showing the GymApp app
SKILLS & TOOLS
C-BASED LANGUAGES
C++ / C / C# — full game & app development, core mechanics and performance optimization
UNITY ENGINE
Game mechanics, physics, UI/UX, 2D & 3D graphics, animation and performance profiling
UNREAL ENGINE
UE 4 & 5, C++ development, profiling (Unreal Insights), UMG and familiarity with blueprint workflow
SOURCE CONTROL
Git & Plastic SCM
PHOTOSHOP
Graphic design, sprite animation, texture creation and web design
AFTER EFFECTS
Motion graphics, visual effects, and animation for in-game cutscenes, trailers, and UI animations
AUDITION
Sound design, editing, and mixing, including music, dialogue, and sound effects
BLENDER
Familiarity in 3D modeling, and rendering for characters and environments in game development
WEB DEVELOPMENT
HTML, CSS & JavaScript: built from scratch, like this site (PageSpeed: 100-100-100-100)
iPad showing the GymApp app
Projects
SHOW-REEL — GUILLE SANCHEZ

Click on any project to see a detailed breakdown of the methodologies, tools, and code used, some accompanied by videos and live demos.
Published Games & Apps

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PLAYERS
Atomic Tiles
updated
Atomic Tiles is a slide puzzle game where the goal is to create the largest atom possible.
Multiplatform development
Gameplay Design
Custom scene management system
Daily Challenges & Rewarded Ads
Native Game Services (Achievements & Leaderboards)
Share Sheets (Screenshot)
Cloud Services (Save & Load System)
Local Save & Load system (JSON)
Native UI & Alert Dialogs
In-App Purchases & Ad Networks
Localization
Handcrafted visuals & animations
Profiling & Optimization

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Poker Chip Counter
updated
Poker Chip Counter is a cross-platform mobile app designed to simplify the management of Texas Hold'em poker tournaments.
Multiplatform development
Cross-Platform Compatibility
Real-time multiplayer system
In-App Purchases & Ad Networks - Mediation
Localization with support for 5 languages
Handcrafted visuals & animations
Real-time server communication
Data structure & Game Logic
Optimized UI

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GymApp Fitness
updating soon
GymApp Fitness is a cross-platform workout planner and tracker app.
Multiplatform development
Complex data structure design and management
Save & Load system of complex data types in JSON
User-friendly and optimized UI
Object pooling and UI recycling techniques
Handcrafted visuals & animations
ADVANCE FEATURES
(implemented but not released)
Cloud-based online/offline Load & Save system for complex data types using the Firestore SDK
User authentication system & data synchronization

TEAM & PERSONAL PROJECTS
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Metroidvania Project
updated
A 2.5D Metroidvania demo developed in collaboration with a small team.
Full Metroidvania Player Controller: movement, jump, dash, attack, block, stunning and parrying system, and more
Enemy AI with: patrolling paths, player detection, block, attack suite with combos, and more
Animation: Player and enemy animation system (full programmatically)
UI: Menu, player's HP, PP & stamina bars, etc.
Particle systems: blood, vfx, rain, fog, etc.
Attack system: default, strong, block & parry
Camera setup with smooth transitions using virtual cameras (cinemachine)

DEMO INCLUDED Demo Included Tag
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Player Controller • HOLLOW KNIGHT
updated
This is a player controller I made by reverse engineering Hollow Knight's. It has the following features:
State machine logic (grounded, airborne, wall-jump, etc.)
Custom hitbox & collision detection
Custom gravity from scratch
Jump velocity using Verlet Integration
Coyote Time & Jump Buffering included
FEATURES IDENTICAL TO HK
Movement speed
Movement acceleration/deceleration
Jump-feel
Jump-peek and land time
Air control feel
Fall-speed cap
Wall Slide
Wall Jump system

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Shards of Eternity • Menu Scene
updated
This is a menu scene I made long ago to test Unity's API, features and tools.
User Interface Design
Interactive navigation
Graphics Options with toggles and sliders
Audio Options with toggles and sliders
Custom Graphics
Custom Animations
Particle Effects
Input Handling and Event System integration

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Pokémon FireRed RandomLocke
updating soon
A RandomLock mod I made by modifying the source code of Pokémon FireRed in C (personal use).
Implemented custom graphics and Pokémon sprites
Random initial Pokémon
Rival's Pokémon are random from start and evolve at the right levels
One random Pokémon per area available for capturing
Gym & Pokémon League leaders have random Pokémon from a pool of their Pokémon type
Level cap based on defeated gym leaders to boost the difficulty
Fainted Pokémon can't be healed and are released from your party

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C++ String Class
updated
An efficient C++ string class I made from scratch.
Aimed at minimizing heap allocations
Contains methods such as reserve, to_string, append, format, and more
x20 faster than Unreal Engine's FString for string interpolation
x10 faster than std::string and .NET string for string interpolation

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Image SSIM Comparator
updated
I created a desktop and web application for quick, side-by-side image comparison.
I took inspiration from Google Squoosh's image viewer, but I wanted the ability to upload two custom images: the original and an optimized version (reduced in file size) from my automated pipeline. The application allows you to visually assess image quality changes and check the SSIM score (Structural Similarity Index Measure) for objective analysis.
Desktop app build with Electron
The desktop app uses Magick Compare for SSIM analysis
The Web application uses SSIM.js for the analysis