Milka AR Advent Calendar
Mondelez / Milka Christmas Campaign
The Milka AR Advent Calendar was a festive mobile experience created for families in the run-up to Christmas.
Users could scan their physical Milka advent calendar to unlock new digital surprises each day. Inside the app, children and families could build their own personalised Christmas town, adding new items as they appeared, customising houses and watching characters come to life with small animated moments.
The experience built towards Christmas Eve, where the user’s own town became the setting for a final fireworks display.
It was a playful, family-focused project, but it also had some interesting technical challenges. The AR marker was the Advent calendar itself, which meant it changed throughout the month as doors were opened. The app needed to keep working reliably even as the physical calendar slowly became less complete.
My Role
Sole Unity Developer
I was the sole Unity developer on the project, responsible for building the app experience in Unity and bringing together the AR, interaction, animation, and content systems.
My role included integrating the illustrated art assets, creating the 2D character animations, building the placement and customisation flow, and making sure the experience ran smoothly across a range of mobile devices, including lower-end hardware.
A big part of the job was making the technology feel simple and reliable. The app was mainly aimed at children and families, so the experience needed to feel easy, charming, and magical rather than technical.
Technical Challenges
One of the biggest challenges was making the AR work reliably across the whole month.
The marker was the user’s physical advent calendar, which changed every day as doors were opened. That meant the app could not rely on the marker staying perfect. It needed to continue recognising and tracking the calendar even as parts of the artwork were gradually removed or damaged.
Another challenge was performance. The app had animated characters, customisable houses, placed objects, and a growing town scene, but still needed to run smoothly on a wide range of devices. I had to be careful with asset integration, animation setup, and scene complexity so the experience stayed responsive.
The content also needed to be built over time. Each day unlocked something new for the user to place in their town, so the app needed a clear structure for managing daily items, user progress, and the final Christmas Eve moment.
The tone of the project mattered too. This was not a technical demo; it was a small, daily Christmas experience for families. The interactions had to feel simple, playful, and rewarding without getting in the way.
Key Contributions
Sole Unity developer on the mobile AR experience.
Built the core app experience in Unity.
Integrated the AR tracking flow using the physical Advent calendar as the marker.
Created the system for daily unlocked items.
Built the town placement and customisation features.
Integrated illustrated art assets into the Unity project.
Created the 2D character animations.
Implemented animated characters and small interactive moments.
Worked on performance optimisation for lower-end mobile devices.
Helped ensure the app remained usable as the physical Advent calendar changed throughout December.
Built the Christmas Eve fireworks moment using the user’s own customised town.
Technologies
Unity, C#, mobile AR, marker-based tracking, 2D animation, mobile optimisation, interactive content systems, character animation, customisation systems, iOS, Android.
Outcome
The Milka AR Advent Calendar turned a traditional Christmas product into a daily interactive experience.
Rather than just opening a door each day, families could gradually build their own festive town, personalise it, and see it come alive through animation and AR. The final fireworks display gave the experience a clear ending and made the user’s own creation feel part of the Christmas Eve moment.
For me, the project was a good example of using Unity and AR in a light, family-friendly way. The technical work was about keeping the experience smooth, reliable and easy to use, so the magic of the calendar stayed at the centre.
