Picture of Leonhard Tissen

LEONHARD
TISSEN

Professional web developer with 7 years of experience

Unleashing creativity on the web

Not only do I have a passion for web development,
but also game development and fullstack development.

Throughout my many years as a developer, I've built
and maintained high quality creations ranging from fun
to providing real value to users.

And I want to continue doing exactly that.

JollyWorld

The sandbox ragdoll game with extensive customization and level editor.

Playable Characters

I created the character selection page along with the character customization built on the modding system. Not only are players able to pick a wide variety of high quality community created characters, but they could create one themselves in seconds using a very performant in-browser image editor. Players that don't want to hand draw their characters could also pick from a wardrobe and have a fully personalized character in seconds that is ready to play right away.

Level Editor Blueprints

The Level Editor for JollyWorld can do pretty much anything, but this vast toolset can lead to an overwhelming feeling for a new level builder. This is why I extended the blueprint system, which allows for level builders to upload their creations in a beautiful, snappy layout. Building a level is a plug & play experience that is like no other.

Level Design

I've also created my fair share of games on the JollyWorld platform. They range from traditional stages to recreations of popular game titles such as Cat Mario and Bad Piggies. Many of my levels have more than 100,000 plays and one even stands at over 500,000 plays, which is the third most played level in the game.
Featured
Web Design
Game Design
Level Design
Backend Development
Server Management
Python
SQL
HTML5
SASS
PixiJS
Jelly's Venture

The fun platforming game in collaboration with the YouTuber Jelly.

Level Design

I built all 25 levels in the game. Jump from a friendly outdoor environment into a mighty lava-filled city or a dangerous factory. All the game elements are introduced in fair ways and used in all sorts of challenges. Designed with replayability in mind, players are challenged to get all 3 stars in the game that requires unveiling secrets and quick movement.

Level Art

I designed all of the tilesets in the game along with all of the game elements. Due to the fast paced gameplay, these needed to be cohesive and not throw you off. I also created some of the backgrounds.
Featured
Game Design
Level Design
Graphic Design
JavaScript
PixiJS
Game Development
Netlify
Doomed.io

The online multiplayer game about gathering resources and building bases.

The game was left without updates for many years, and with an established community that has brought some challenges. My goal was to improve the playing experience overall.

Reimagined UI

Nearly all of the UI elements have been redesigned to be more performant, adapting to different screen sizes and overall being more cohesive and understandable.

Anti-Cheat

Over time, more and more players have used cheats to break the game in various ways and one of my main goals was to prevent this. Nearly all cheats have been patched to allow for a fair playing field and a great experience for new players that are still learned the environment.

Mobile Support

I made the game playable on mobile devices and tablets by making all actions compatible with touch controls. This came with a lot of challenges but I managed to pull it off without adding any more UI clutter.

Game Content

A large portion of my contributions was ironing out existing world elements, but I even added my own resources and items, like the cactus and grappling hook.
Featured
Graphic Design
Game Design
Web Design
Backend Development
Java
TypeScript
PostCSS
HTML5
WebSocket
Kubi Pets

The addicting game about unboxing pets and merging them.

Unlimited Gameplay

The game is designed to be endless but remain rewarding. There is always a new pet to discover. Prestiging allows for replayability without the game becoming mundane.

Upgrade Islands

Instead of getting your upgrades in a GUI, you have to walk to different islands.

Mobile Support

Unbox pets on the go with joystick controls.

Performance

The game was designed to handle hundreds of simultaneous pets with thousands of coins coming out of them.
Featured
Graphic Design
Game Design
ThreeJS
CSS
JavaScript
HowlerJS
Python
Webpack
Netlify
Serpentario Educativo

The argentinian wildlife rescue center dedicated to conservation and environmental education.

Website

I was contacted to build a website for the rescue center who previously only had an online presence of social media accounts. The site compiles all the useful information about them in a pretty color scheme. I even made custom icons for their homepage.
Graphic Design
Web Design
CSS3
JavaScript
Python
Web Design
HTML5
Netlify
WartOSView Repository

The web-based operating system.

Desktop Experience

The place that simply lists out all my projects would be too boring. Instead I built my own operating system-like website where you can open my projects as programs. Customize your wallpaper or upload your own!
Featured
Graphic Design
Web Design
Backend Development
Server Management
Flask
Python
Jinja
OAuth
JavaScript
VueJS
Webpack
Netlify
TypeScript
CSS3
Permaplace

A place where every pixel lasts a lifetime.

Social Experiment

An ongoing social experiment inspired by r/place. Placing a pixel is completely anonymous and can be done every 5 seconds.

Giant Canvas

A 10000x10000 canvas brought a plethera of challenges. Pixels are stored in a custom format that loads incredibly quickly on any device to allow instantaneous placing of pixels. Due to the immense size, permaplace will never be fully filled, but that means there is always space for you.

Collaboration

Due to the time cooldown, you are incentivised to work together with friends. And that's exactly what people did. Giant creations were formed only made possible through teamwork and coordination, because remember: Any previously placed pixel can never be removed.

Custom Rooms

Users are able to create their own rooms with smaller canvas sizes and less restrictions.
Backend Development
Server Management
SQL
Python
Jinja
HTML5
JavaScript
CSS
Databases
r/place
Casino BotView Repository

The open source Discord bot with various games and economy aspects.

Text-based Games

All games can be played within a Discord server. The bot has both singleplayer and multiplayer games with various rewards.

Economy

Collect diamonds and chests which can be used for trading with other users. Become the richest in the server!

Customization

Users can customize various aspects of games such as cards, colors and chips.
Graphic Design
Game Design
Backend Development
Server Management
JavaScript
NodeJS
SQLite
Lights On!View Repository

The puzzle game where you need to turn all the lights on.

A remake of a popular puzzle game with more fleshed out puzzle design. Can you solve all 14 levels? Turn all the lights on, it shouldn't be that hard... right? With each click, adjacent lamps toggle and you have to fiddle around to find the right pattern.

In the bottom left, you can see your own clicks and the ideal amount of clicks needed to solve the level. Don't worry, you can keep clicking beyond the perfect score without being punished and your progress is saved even if you close the tab.
Graphic Design
Game Design
TypeScript
PixiJS
Netlify
HowlerJS
Level Design
Lights On! 2View Repository

The puzzle game where you need to illuminate the room.

Can you beat all 20 levels? Some light bulbs are stronger than others and you need to fully understand them in order to master the puzzles. Some levels have multiple solutions, others can take a bit to get right.
The game has slick animations for UI as well as breathtaking sound design that will give you chills.
Your progress is saved, so you can always continue where you left off.
Graphic Design
Game Design
TypeScript
PixiJS
Netlify
HowlerJS
Level Design
Flag QuizView Repository

The fast paced flag quiz.

For all types of players

Various difficulties and game modes to intuitively learn flags and their origins.

Speedrun timer

Challenge your friends by daring them to get a faster time than you in a particular game mode.
VueJS
HTML5
TypeScript
PostCSS
TailwindCSS
Netlify
Web Development
JavaScript
Webpack
CSS
Discord Emoji StatusView Repository

The tool for discord customization.

Customize your profile

Make your discord profile pop using emojis by pasting a pixel of any kind. This tool provides an intuitive interface to create, share and experiment. Use it in your about me, your status or just in any chat where emojis are supported.

Popular on Reddit

The tool initially blew up on Reddit in 2021 but I decided to rewrite it in under 24 hours using modern web technologies and an overhauled user interface. The reception was immensely positive.
VueJS
HTML5
TypeScript
PostCSS
TailwindCSS
Netlify
Web Development
JavaScript
Webpack
CSS
Ball 2 RemakeView Repository

A pixel-perfect remake of a really old game from ~2000

Classic Gameplay

Control the ball with the arrow keys and collect all the diamonds to advance to the next level. Avoid spikes and monsters and use the environment to your advantage.

Level Editor

Build your own levels and share them with your friends to challenge them.

Added Features

Added a lot of new features to the game that weren't in the original, such as a level browser and new game elements,
Game Design
Level Design
Graphic Design
JavaScript
Game Development
Netlify
HowlerJS
HTML5
CSS3
SQL
Python
Web Development
Backend Development
Server Management

Please contact me at the following e-mail.

I'd love to hear from you!

[email protected]