Yibing
Chen
Game Designer & Level Designer
AI2U: With You 'Til The End
Team Size: 15 | Engine: Unity 3D | AlterStaff Inc. [August 2023 - Ongoing]
My Roles: Principal game designer, level designer
Steam: AI2U: With You 'Til The End
Sales: 80,000+ units
Wishlist: 180k+
AI2U: With You 'Til The End (originally known as Yandere AI Girlfriend Simulator) is a first-person escape room game where players must break free from characters desperate to keep them forever.
AI2U features unpredictable characters with dialogue powered by a large language model (LLM). Along with interactive puzzles, players must use their words to negotiate with or outsmart their captors. Explore the environment, and discover the mysteries that lie in each level. No two runs are ever the same; every playthrough offers unique interactions, unpredictable character behaviors, and unlimited paths to freedom.
Responsibilities
I joined the studio at its founding in 2023, helping to shape AI2U from concept to Early Access. During this time, I contributed to shipping levels 1–5 from initial Open Beta to V0.9.2.
Game Design
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Created detailed design documentation for each level.
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Iterated levels, puzzles, and narratives based on playtest and community feedback.
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Fine-tuned AI NPCs' prompts to create an immersive conversational gameplay experience.
Level Design
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Designed and greyboxed levels in Unity 3D.
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Set-dressed the level with environmental assets.
Narrative Design
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Wrote the main story and designed individual narratives for every level.
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Created distinct personalities and backgrounds for all non-player characters.
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Wrote scripted dialogue and on-screen text.
Production
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Managed design team's schedules and task tracking to ensure smooth cross-team collaboration.
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Managed task tickets using Azure DevOps.
Gameplay Design - Structure & Design Challenges
Level 2 - Witch's Cabin
Level 4 - Siren's Island
AI2U's uniqueness came from its deep incorporation of LLM-powered conversation, which provided players with an infinite number of dialogue possibilities. In some levels, players could even escape solely through conversation without solving any puzzles.
However, this created two distinct design challenges:
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Without traditional structural boundaries, players often felt overwhelmed by the open-ended nature of the gameplay.
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Some players were not used to conversation-based gameplay and gravitated toward traditional puzzle-solving.
Balancing Guidance and Freedom
To tackle the first challenge, I used the following ways to balance the in-game guidance and player freedom:
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Prompt design: NPC guiding players to certain actions through immersive dialogues.
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Level design: Visible end and/or stage-by-stage goals in physical worlds.
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Game design: Implement short tutorials, then reinforce the gameplay by making level 1 contained and with a straightforward loop.
The NPC gently nudges the player toward certain interactions while maintaining her distinct personality.
After building trust, the NPC will provide more helpful hints to the player's questions when asked.
Level 3 has the biggest map of all the levels. To avoid player confusion, I divided the level into smaller sections that the players can unlock gradually.
When the player spawns in this level, they almost immediately see the locked doors, which prompts them to discover ways to unlock them.
I designed the tutorial sequence and dialogue to introduce players to the core mechanics: chatting (via text and voice), interacting with the environment, and using items.
I iterated on the tutorial many times based on internal and community playtest feedback.
Encouraging Player-NPC Conversations
To tackle the second challenge, I used the following ways to incentivize players to converse with the NPCs:
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Multiple endings
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Hidden character stories
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NPC behaviors
Multiple Endings: Each level features multiple endings. Talking to the NPCs unlocks additional gameplay, which in turn leads to more varied and favorable endings.
Hidden Character Stories: Each NPC has a deep, personal story. They will only share it once they trust the player.
NPC Behaviors: NPCs will only show explicit affection if they trust the player.
Level Design
When designing each level layout, I followed these rules:
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The layout should adhere to the level theme.
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Include a hidden, 'dark' area and related story twist for dedicated players to discover.
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Ensure every room or area has a Point of Interest (POI) that triggers player curiosity and NPC reactions.
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Manage the map scale to avoid levels becoming too large.
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Design within strict time and resource constraints.
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Minimize player downtime between interactive elements.
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The game features four core levels and a final chapter that concludes the story. While the ultimate goal is always to escape your captor, I wanted players to have a fresh experience with each level. My goal was to balance the design to satisfy two distinct audiences: puzzle enthusiasts seeking a challenge, and casual players who prefer to relax and interact with the NPCs.
To achieve this, I designed each level based on a unique theme, a distinct gameplay focus, and a character with a unique personality.
1. Catgirl's Apartment
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Environment:
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Modern apartment building
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Gameplay Focus:
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Conversation-focused, introductory level
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Character:
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Yandere catgirl
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This level is the smallest in scale and has a relatively small number of endings. Its purpose is to ease players into the game mechanics while providing ample replayability.
We also experimented with several NPC-environment interaction features in this level, including the NPC dynamically reacting to player-uploaded videos and customized drawings.
2. Witch's Cabin
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Environment:
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Magical cabin
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Gameplay Focus:
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A mix of conversation and puzzle, deeper lore
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Character:
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Curious witch
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This level subverts the expectations set by the previous level: the door here is not locked. Instead, the player must find a way to navigate an outdoor maze unscathed in order to escape.
3. Cosmic Funeral
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Environment:
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Futuristic space station
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Gameplay Focus:
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Puzzle-focused, linear sequence
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Character:
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Rational hologram
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This is the biggest level in AI2U, and it took the longest to balance. To avoid player confusion, I divided the level into smaller sections, each containing puzzles and interactive objects. Players need to solve the puzzle in each section to gradually unlock the entire space station. This created a more linear gameplay experience, offering a distinct change of pace from the other levels.
4. Siren's Island
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Environment:
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Tropical island
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Gameplay Focus:
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Companionship-focused, open environment to relax with the NPC
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Character:
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Sassy siren
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Drawing from the experience of designing the previous level, I dialed down the scale for this level. Instead of setting it indoors like a traditional escape room, I designed it as an open island. This provided a nice contrast to the enclosed rooms of the prior levels, offering a relaxing environment for players who enjoy companionship more than puzzle-solving.
4. Final Level
This is the final level of the game, where the player will revisit all four characters and their worlds. Here, the player will make a series of choices that will determine the final ending of the game.
To make both the levels and the NPCs more immersive, I worked with the development team to incorporate NPC responses to level POIs. For example, in Level 1, the player can draw on a canvas, and the NPC will give a unique comment on the artwork each time. In Level 4, the NPC can sometimes transform into a mermaid depending on the scenario. Moments like these encourage players to explore both the environment and NPC interactions more deeply throughout their playthroughs.
LLM Prompt Design
I worked closely with our back-end and development teams to design the prompts for each NPC to achieve the following goals:
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Establish distinct characteristics for each character.
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Create an immersive conversational experience for the player.
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Embed a layered story that the player could discover over the course of their playthroughs.
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Provide sufficient guidance while preventing the NPCs from leaking all information at once.
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Minimize token usage and operational costs.
We initially used OpenAI and later switched to Gemini. To adapt to different LLM models and achieve our goals, I co-led multiple AI benchmark playtests to compare and test different prompt formats. I compiled the playtest data and organized it into clear documents for other teams to evaluate.
I conducted numerous rounds of internal playtests and community feedback collection to gather consensus for each version of the prompt. I would then work with the back-end team to improve the prompt structure and content to optimize the game.
Over two years of improvements, our NPC conversation experience was highly praised by our community, and we successfully reduced back-end operational costs significantly.
Project Management
New Level Development Planning
For every new level, I created the initial design documentation and gathered feedback across departments. Once all teams reached consensus, I converted the design into actionable tasks and categorized them into MVPs with input from the development team.
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MVP 1 - Must-have features: the level can run with these basic functionalities done.
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MVP 2 - Great-to-have features: would greatly improve the game experience.
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MVP 3 - Polishing features: would help the level be better, but can be cut depending on time.
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MVP 4 - Reach goals: if we still have time, these would help polish the level even more.
Once the MVPs were set, I handed them to the Design and Development teams for time estimation. I then refined the tasks and timelines as necessary before delivering the list to my lead for sign-off. In parallel, I mapped out the required art assets and worked closely with the art team to build their production schedule.
Daily Operations
Every Monday, I led weekly planning syncs with the design team to map out upcoming tasks. I would then communicate these tasks with other team leads to ensure all teams are synced on current objectives and priorities.
Additionally, I co-hosted the Dev & Design Daily meeting, a stand-up meeting for design and development teams, and managed all design tracking tickets within Azure DevOps.
Awards
