The Blocktoberfest Game Jam 2025 is now live, bringing together game makers, artists, and horror fans in a 4-week online event built inside the browser-based Portals platform. This year's jam runs from September 26 to October 24, with a $50,000 USD prize pool and official support from Atari® and Block of Horror™.

Participants can use iconic game titles from both partners to create playable scenes or 3D artwork using Portals' no-code tools. All projects must be submitted by October 23, with judging to follow from October 25 to October 30. Winners will be revealed during a public showcase from October 31 through November 3, right during Halloween week.

A Horror and Gaming Mash-Up

Blocktoberfest 2025 marks a partnership between Portals, classic game brand Atari, and community-driven horror platform Block of Horror. The goal is to inspire global creators to build interactive or visual projects that remix the style, story, and mood of each partner's selected games.

This jam is open to everyone, from veteran developers to first-time builders. Using just a browser, users can build scenes and game logic without writing any code. The event encourages horror themes and creative reuse of game worlds from both IP catalogs.

What You Can Build

Participants must choose one of three tracks: Atari, Block of Horror, or the Artist Track. Games must be built using Portals, which works entirely in the browser with drag-and-drop tools and a visual logic editor.

Each project must have a clear start and finish (or loop structure), be playable online, and use only the allowed game titles listed under each track. Scenes can feature recognizable settings, characters, or stories from the selected games, but original twists are welcome.

Atari Track

For the Atari track, creators can pull from a list of retro horror and sci-fi titles, including Haunted House, Dracula: The Undead, Shark Jaws, Alien Brigade, and others. The focus here is to bring these classic settings into a modern 3D browser format, while keeping gameplay, pacing, and visual tone tied to the original.

Block of Horror Track

The Block of Horror track gives access to new horror worlds from indie creators. These include CARRION, HELL FROZEN OVER, HOW I BROUGHT ABOUT THE END OF THE WORLD, and more. Submissions on this track are expected to use the eerie, offbeat tone that Block of Horror titles are known for.

Artist Track

This dedicated track is for 3D artists who prefer to showcase visuals rather than gameplay. These scenes can be still or walkable, but do not need game logic. Artists can design inside Portals or import GLB models. Judging is based on design, atmosphere, and visual storytelling tied to an approved Atari or Block of Horror title.

Rules and Format

All work must be made using Portals, and all entries must be submitted by October 23 at 11:59 PM UTC. The project must load smoothly in the browser, and any game logic should be clear and functional.

The use of NSFW, plagiarized, hateful, or abusive content is banned, and every project must follow the event's Code of Conduct. Each entry must make clear use of the selected IP.

Judges will explore the scenes and games directly in-browser through the Portals platform.

$50,000 USD Prize Pool

A wide range of prizes is up for grabs. The total pool is split into Big Prizes and Mini Prizes, judged separately.

Big Prizes

There are first, second, and third place cash awards for each of the three main tracks.

Atari Track

  • 1st Place: $10,000
  • 2nd Place: $7,500
  • 3rd Place: $2,500

Block of Horror Track

  • 1st Place: $10,000
  • 2nd Place: $7,500
  • 3rd Place: $2,500

Artist Track

  • 1st Place: $2,500
  • 2nd Place: $1,500
  • 3rd Place: $1,000

Mini Prizes (Community's Choice)

These awards are based on community voting and recognize standout moments in design or atmosphere.

  • Scare Award (Best horror moment): $1,000
  • Shocker Award (Best twist or reveal): $1,000
  • Creativity Award (Most original use of IP): $1,000
  • Community Award (Most voted game): $2,000

How Judging Works

Judging happens from October 25 to October 30. Each track has its own set of rules, and judges will score entries from 1 to 10 in five areas. Ties are broken by group vote.

Game Tracks (Atari and Block of Horror)

Submissions here are judged on:

  • How well the chosen game IP is used
  • The gameplay and moment-to-moment design
  • Horror mood, atmosphere, and sound
  • Browser performance and overall polish
  • Creativity and new ideas

Artist Track

Visual entries are scored on:

  • How well the chosen IP is shown
  • Quality of models, lighting, and textures
  • Scene layout and focus
  • Clean assets and fast load times
  • Originality of the design

The IPs You Can Use

Each track has a locked list of allowed titles. Only these are allowed in submissions.

Atari Titles

  • Haunted House
  • Dark Chambers
  • Dracula: The Undead
  • Shark Jaws
  • Witch Hunt
  • Black Widow
  • Demons to Diamonds
  • Alien Brigade

Block of Horror Titles

  • BUG SUCKERS
  • CARRION
  • HOUSE
  • DEVIL-A-POD
  • GIANT MONSTER: DESTROY
  • HELL FROZEN OVER
  • HOW I BROUGHT ABOUT THE END OF THE WORLD
  • LEFTOVERS
  • MUTANT MANIAC
  • THE NIGHT CHILDREN
  • TRANSFORMATION OF THE WOLF
  • XENON SPACE RIDERS

Halloween Showcase

From October 31 to November 3, a public showcase will go live featuring all qualified submissions. This online event will highlight the winners from each track, plus community favorites. Fans and developers can play games, walk through art scenes, and vote for their top picks.

What is Portals?

Portals is a browser-based platform for building games and 3D scenes without using code. Often called the "Roblox of Web3," it lets anyone create and share immersive spaces entirely within a browser; no downloads or installations needed. You can start building right away using a drag-and-drop editor, then add logic and interactions through simple visual tools.

The platform supports instant testing and publishing, with scenes that load fast and run smoothly. No technical background is required. Whether you're building a short horror game or a rich visual showcase, Portals offers a quick way to create and explore digital worlds with web3 integration.

Entry Details

The deadline to submit is October 23, 2025. Submissions must meet all format rules, follow the event Code of Conduct, and use only the allowed game titles from Atari or Block of Horror.

All scenes should load quickly in-browser and include clear start and end points. Artist Track entries can be non-interactive but should still focus on mood, polish, and visual storytelling.

Winners will be revealed on Halloween week, with all entries viewable online during the public showcase. Whether building a creepy game or showing off a dark 3D scene, all creators must use Portals and stay within the selected IP list.

For more info, visit the official Portals platform and follow updates as the game jam continues.