Deer & Boy is a cinematic platformer where a runaway boy bonds with a baby fawn across 10 distinct areas. There are no chapter breaks in the game itself, just one continuous journey, but the structure underneath is clear: sneak past enemies, solve environmental puzzles, and guide your deer companion through obstacles that neither of you can handle alone. The deer grows as the story progresses, and so do your options for how to interact with it. This guide covers every section from start to finish, plus everything you need to lock down all 28 achievements in a single run.
The journey begins here
What kind of game is Deer & Boy?
Deer & Boy sits firmly in the adventure games tradition of story-first, mechanics-second design. There is no combat system, no health bar, and no upgrade tree. The challenge comes from reading each environment, figuring out where to position the deer, and knowing when to carry it versus when to let it roam. The game communicates almost entirely without words, which means paying attention to visual cues is more important than following dialogue prompts.
The developers recommend playing with a controller, and that recommendation holds up. A controller connected via Bluetooth works even through Steam, so there is no reason to wrestle with keyboard inputs if you have one available. For reference, the core controls you will use constantly are: jump, hold and release over an object to guide the deer toward it, grab or press objects as the boy, and call or pick up the deer.
How does the deer's growth change gameplay?
The fawn starts small enough to carry, and that physical relationship shifts as it grows through each stage. Early on, cuddling and carrying are your main interactions. As the deer grows, you gain access to high-fiving, riding, and eventually using its special abilities to interact with the environment in ways the boy cannot manage alone.
This growth is not just narrative flavor. Each new size unlocks puzzle solutions that were not available before. Areas designed around a small deer require different thinking than areas where you can ride it. The game sequences these changes deliberately, so you will rarely feel like an ability appeared without warning.
Growth changes what you can do
The missable achievement you need to know before starting
Out of 28 total achievements, only one is genuinely missable in a way that could lock you out without a second playthrough: Best Friend Forever.
This achievement requires cuddling the deer at every stage of its growth, from the earliest moments through the end of the game. Miss a single growth window and it will not trigger. The cuddle input is D-Pad Down on controller or C on keyboard.
Every other achievement can be earned naturally through story progression or by completing puzzles cleanly on the first attempt, which includes avoiding detection in stealth sections.
All 10 walkthrough parts at a glance
The game splits into 10 distinct sections, even though there are no in-game chapter markers. Here is the full sequence:
Stealth is core to early sections
How do you complete puzzles without getting caught?
Stealth in Deer & Boy works on visibility and sound. Enemies patrol set routes, and the boy and deer both generate detection risk. The key is sequencing your movements so the deer is never in an enemy's sightline while you are also out of position to redirect it.
Before moving through any guarded area, watch a full patrol cycle. Most enemies have predictable loops. Once you know the timing, the puzzle becomes about moving the deer first, then following, rather than both of you moving together. The deer will go where you guide it, but it will not wait forever, so your window for repositioning yourself after directing it is limited.
For achievements tied to clean stealth runs, the first attempt matters. Restarting a section after being spotted does not reset the achievement condition in some areas, so treat each stealth section as if you only have one shot.
Can you earn all 28 achievements in one playthrough?
Yes. Every achievement in Deer & Boy is available in a single run, provided you handle the Best Friend Forever cuddle requirement across all growth stages and complete the relevant stealth sections without being spotted on the first attempt. Most achievements unlock automatically as you reach story milestones. The ones that require active attention are the stealth-based achievements and the cuddle chain.
Keeping a mental note of which growth stages you have cuddled at is the simplest way to stay on track. The game does not provide a tracker for this, so the responsibility falls entirely on you.
Where to find more Deer & Boy help
This overview covers the full structure of the game and the achievement strategy you need going in. For section-by-section puzzle solutions and detailed area breakdowns, the Deer & Boy strategy guides collection has dedicated pages for each of the 10 parts. If you get stuck on a specific puzzle or stealth sequence, that is the place to dig into the details.