[C01] MUSH UP

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Inspiration

We were inspired by joyful vertical games like Doodle Jump, Mario, and the minimalist beauty of Monument Valley — but wanted to reimagine that upward-jumping experience in a mushroom-shaped world filled with playful interactions and hidden meaning.

We imagined a world once full of vibrant mushroom life, now withering due to pollution. Players climb through mushrooms, trees, and cloudy skies to reach the SunShroom (the mushroom angel) and save the MushWorld — not just to win, but to bring life back by reaching the purest mushroom at the top.

The game is designed to feel lighthearted and communal, yet carries a gentle narrative about recovery, curiosity, and interconnected effort — whether alone or with others.

What it does

MushUp is a multiplayer jump-up game for Mobile, VR, and PC, built in Meta Horizon Worlds.

Players begin on the ground of a once-thriving mushroom world and must leap upward through layered environments — mushrooms, trees, and clouds — to reach the legendary Sunshroom, a glowing mushroom angel said to hold the power to heal the world.

On their journey, players can ride snails, bounce off ladybugs, float with balloons and hot-air balloons — but must beware of aggressive birds that try to knock them down.

The faster and higher you reach the Sunshroom, the higher your score — and the more you contribute to restoring the MushWorld.

You can play solo or with friends, uncover hidden areas, or simply enjoy bouncing through the skies. Everything starts with one jump.

How we built it

We built everything from scratch in Horizon Worlds within 2 days. Our team of 2 developers and 2 designers collaborated closely on:

World-building & environment design

Scripting jump mechanics, NPC behaviors, and scoring logic

Custom 3D asset creation for Mushroom, Tree, leaves, hot balloon, balloon, bird, ladybugs, final Sunshroom

Avatar interactions, feedback systems

Recording voice-over, sound effects, and trailer editing

Challenges we ran into

Designing a vertical world layout in Horizon Worlds was a technical and creative challenge — we had to carefully balance performance, scale, and visual clarity.

Implementing NPCs and mechanics that encouraged social interaction while staying within a tight development schedule required prioritization and fast iteration.

We faced unexpected challenges during publishing, that we have to duplicate worlds and manually rebuild assets, which cost additional time.

Scripting diverse movement types, demanded fine-tuning to make the experience feel dynamic yet stable, and to minimize VR motion sickness.

Accomplishments that we're proud of

We completed a full vertical platformer experience with custom 3D assets and movement mechanics — all within just 2 days.

The world is visually consistent and harmonious, with all core gameplay features functioning as intended.

It now runs smoothly and supports both VR and mobile players in Meta Horizon Worlds.

The entire trailer was scripted, voiced, and edited by our team — including original 2D assets and logo.

What we learned

How to design upward-movement gameplay that feels fair, fun, and comfortable in VR

How to incorporate NPCs that enhance dynamics and social interaction, while staying true to the world setting

How to collaborate in real time using Horizon Worlds’ in-world editor

How to balance visual storytelling with mechanical clarity in immersive environments

That even a surreal, whimsical game can carry emotional tone and subtle narrative weight

And — that mushrooms make surprisingly great level platforms 🍄

What's next for Mush Up

Adding leaderboards and multiplayer achievements

Multiplayer colaborative interactions like player A hold mushroom to help Player B to jump

Introducing seasonal modes (fog, wind, floating spores...)

Making customizable mushroom avatars, props to carry like flag

Add the effect on how Sunshroom helps to save the world to add on the feedback, make the game more rewarding, encourageing

Creating a full "MushWorld" series with linked worlds and stories

Built With

• blender
• horizon
• meta
• typescript