Castle Survivors: Seventeen Worlds, Co-op and the Road to Steam

The previous post left Castle Survivors with an island, ninety weapons and bosses. This is the story of the ten days that followed, in which it became a game you can hand to testers.

Seventeen worlds

The island got themes, and then siblings. First the islands in the sea: Spring Isles, Autumn Hollow, Frostward Isle, Coral Atoll, Ember Peak and Mirewood. Then five lands that are not islands: Cascade Valley, walled by cliffs, with waterfalls and a river with bridges; Bamboo Grove, with moon gates and a stream; Sky Peaks, a plateau over a sea of clouds; Terraced Hills, with wheat terraces and farmhouses; and Moonlit Garden, walled, with a canal round the castle and lanterns. Finally Sakura Sanctuary, by day and by night, Lantern Festival, Stilt Village, Ruined Temple and Rose Garden. Each world has its own colour grading and bloom, and particles in the air: petals, leaves, fog banks, sun shafts, waterfall spray. The lanes, the castle and the simulation are the same everywhere; only the look changes. Maps are challenge rewards: each themed challenge skin unlocks a world, and the map cards show the island drawn.

Faithful to 1.91 to the end

A full fidelity pass closed what was left of the original map: mana shield, night lighting, the upgrade pools, the Philosopher's Stone, the kill bounty fields, Transmute, burn, the degeneration Ankh, Set Seed and the Daily Seed. The scoreboard shows 1.91's values, there is a DPS meter, a build summary, personal damage and income records, and damage-type marks. The host picks the match speed: 1×, 1.5× or 2×. AI rivals come in Easy, Normal and Human, and the Black Market joined the command card as a secret shop.

How it plays, and how you learn it

The HUD gained four layouts: Default, TFT, Imp and Dota, and the tower picker was redesigned, with castle snapshots on the skin cards. There is an endless solo mode, Beyond Samwise, and mythic endings for the Clear, the castle's fall and victory. First Battle is a guided three-minute tutorial, with smart hints over the shop after it. Builds can be saved and shared by code. Every key is rebindable, with Warcraft III's grid style for the command card, and there are pings with a radial wheel, markers in the world and on the minimap and edge arrows.

In multiplayer, Quick Match fills rooms that start on their own, and the lobby came alive: vote-kick, a bot takes over whoever goes AFK, invite in one click. There is a war room, standings on the HUD and the option to watch rivals on their own map. Crashes and errors are logged, with an error panel in the game and a bug report (F8) that produces a file to send.

For more people

Accessibility: colour-blind palettes, including the lobby's player colours, flash intensity and fewer particles. Languages: the whole interface was extracted into dictionaries and translated to Brazilian Portuguese, then to Japanese, Simplified Chinese and Korean. The Steam Workshop takes mods: data-only gameplay mods and cosmetic mods, with a Modded leaderboards tab and the choice to keep or remove a room's mods. Achievements and unlocks were checked as reachable under 1.91's rules, and every map can be unlocked.

The road to Steam

The game's icon comes from its own crest, embedded in the executable. Every art, music and sound pack shipped has its licence noted and its credit on the credits screen, and 49 MiB of unused material left the package. One command, steam:build, makes a Steam test build of any commit. The Steam docs describe the release state.

A hardened network, and the engine on screen

On the 24th and 25th came a security round: the window under a strict content policy with permissions refused by default, a seat proven by a secret key rather than the install id, oversized envelopes refused before they leave, the room chat bounded, and saves written durably and in order, never overwriting a profile this build cannot read. And Castle Survivors started drawing with Kastle: the engine that came out of it returned as a submodule, for the render layer only (the missile looks and the MOBA ultimates came along). The simulation, the network, the interface, the saves and the replays stay its own. The game's data goes to Kastle Studio and the edits made there come back into the game.

— The team