Undertow Explorer
Descend the drowned wreck.
Wash up on a wreck that shouldn't still be sinking, with a cutlass and one way out: down. A traditional turn-based roguelike of rotted decks, hidden curses and permadeath — where every dive is a brand-new wreck.
Screenshots
iPhone
iPad
A wreck that fights back
Turn-based and grid-based, with no reflex to save you — only the move you choose. Read the room, pick your fights, and know when to run.
Fight smart, not fast
Nothing moves until you do. Every step, swing and swallowed potion costs a turn — and the wreck takes its turn straight after.
Permadeath, every time
Death is permanent. There is no save to reload and no second chance — just a fresh wreck, generated from scratch, waiting for the next dive.
Four ways to drown
Corsair, Tidecaller, Smuggler or Harpooner. Each starts differently armed and cracks the wreck open its own way.
Loot you gamble on
Every potion is a mystery colour and every scroll a nonsense rune until you risk it — and the disguises are reshuffled for each new run.
Systems that bite
Hunger, curses, armed traps, hidden doors, tiered locks, brewing at the alchemy pot, and shops set up in the flooded dark.
Built for the long dive
Daily and custom seeds, a journal that remembers your last fifty deaths, thirteen achievements, and keyboard and controller support.
Everything you need for your first dive
The same guide lives inside the game — the title screen's How to Play button opens it any time.
The dive
- You're wrecked on a drowned ship. Descend deck by deck, cut down what crews the wreck, and go as deep as you can.
- Death is permanent — every run is a fresh dive.
- Twenty-five decks stand between you and whatever is holding the ship down.
Moving & fighting
- Tap a neighbouring tile to step.
- Tap farther off to auto-walk — it stops the moment something appears.
- Tap an adjacent enemy to strike it; tap a distant one to close in.
- Tap a shut or locked door to open it. Locked ones need the matching key.
- Tap yourself to wait a turn — or, standing on stairs, to take them down.
The bottom bar
- Pack — your gear. Equip weapons and armour, read scrolls, drink or throw potions.
- Search — comb the adjacent tiles for hidden doors and traps.
- Wait — let a single turn pass.
Gear & survival
- Walk over anything on the floor to pick it up.
- Potions and scrolls start unidentified — using one reveals it, and some bite back. Potions can also be thrown to burst into gas or fire.
- Reforge scrolls upgrade a chosen weapon or armour. Beware curses — they weld on until cleansed.
- Watch your hunger. Eat rations before the wreck starves you.
Keyboard & controller
Connect a hardware keyboard or a game controller and the on-screen controls step aside. Handy on iPad and Mac, where most people play with one attached.
| Key | Action |
|---|---|
| ←↓↑→ | Move west, south, north, east |
| HJKL | Move west, south, north, east |
| YUBN | Move diagonally |
| . | Wait a turn |
| S | Search adjacent tiles |
| R | Rest |
| G or , | Pick up |
| > / < | Descend / ascend stairs |
| I | Open the pack |
| Esc | Cancel |
| Control | Action |
|---|---|
| D-pad or left stick | Move in eight directions — hold to repeat |
| A | Confirm — and take the stairs |
| B | Cancel |
| X | Search |
| Y | Wait |
| Menu | Open the pack |
Using, throwing and zapping items stay on the touchscreen — they need you to pick a target.
Five regions, twenty-five decks
Every five decks the wreck changes character — new layouts, a new crew of horrors, and something large waiting at the bottom of the region.
The Wreck
Rotted timber and rising water. Guarded by the Bilge Blight.
The Brig
Cells, locks and things that were prisoners once. Guarded by the Phantom Bosun.
Reef Caverns
The sea has taken over from the shipwrights. Guarded by the Salvage Engine.
The Drowned City
Something down here was built, not wrecked. Guarded by the Drowned King.
The Hadal Abyss
No light, no surface, no way back. Guarded by That Which Sleeps Below.
Kill what waits on deck twenty-five and the dive is won. Nobody has to know how many attempts it took.
Pick your way down
Each class starts with different gear and one trick the others don't get.
| Class | Starts with | Edge |
|---|---|---|
| Corsair | Cutlass, sealhide armour, two rations | Stronger from the first turn, and already knows a potion of strength on sight. |
| Tidecaller | Boarding knife, oilskin, a ration, a scroll of upgrade | Sees further into the dark, and recognises upgrade scrolls without testing them. |
| Smuggler | Boarding knife, oilskin, a ration, a potion of healing | Starts the run invisible, and hits far harder from surprise. |
| Harpooner | Boarding knife, oilskin, a ration, a harpoon to throw | Sees straight through kelp, and can throw weapons too heavy for their grip. |
Thirteen achievements
Twelve to chase, and one you'll only find at the bottom. Game Center is entirely optional — the game tracks your badges locally either way.
Questions before you dive
What is a “traditional roguelike”?
It means turn-based, grid-based, procedurally generated and permanently deadly. Nothing in the wreck moves until you do, so there's no reflex test — but when you die, that run is over for good and the next one takes place in a wreck you've never seen.
Is there really no way to undo a death?
No. The game saves your run so you can put your phone down mid-dive and come back to it, but that save is cleared the moment the run ends. There's one run at a time and no reloading a bad fight.
Are there ads, in-app purchases or subscriptions?
None of the three. Undertow Explorer is a one-time purchase with the whole game in it. There are no ad SDKs, no purchase prompts and no premium currency.
Does it need an internet connection?
No. The game is entirely offline and makes no network requests of its own. The only online feature is Game Center, which is optional, handled by Apple, and which the game works fine without — on a plane, in a tunnel, or in Airplane Mode.
What devices does it run on?
iPhone and iPad running iOS or iPadOS 18 or later, plus Mac. On iPhone the game plays in portrait; on iPad it works in any orientation.
Can I play with a controller or keyboard?
Yes. Connect a hardware keyboard or a game controller and the game picks it up automatically — a small controller glyph appears in the corner to confirm. See the full control list above. Selecting an item to use, throw or zap still happens on screen, because it needs you to pick a target.
What are seeds, and what's the daily seed?
A seed is the number the whole wreck is generated from. Leave it blank for a random dive, or type anything you like — a number, or a word like kraken — and you'll get the same wreck every time you use it. Share a seed with a friend and you both dive the identical ship.
The Daily button fills in today's date, so everyone playing that day gets the same wreck.
Why can't I tell what my potions do?
Potions, scrolls, wands and rings all start disguised — a colour, a rune, a wood, a gemstone — and the disguises are shuffled fresh for every run. Drinking, reading or wearing one identifies it for the rest of that dive. Some of them bite. Working out what's safe is the game.
Two shortcuts: the Corsair already recognises a potion of strength, and the Tidecaller already recognises a scroll of upgrade.
How do I actually win?
Reach deck twenty-five and kill what's waiting there. The four region bosses above it drop a hoard and clear the way down, but only the thing at the bottom ends the dive in victory.
Does the game keep a record of my runs?
Yes — the Journal on the title screen keeps your last fifty dives: class, seed, how deep you got, turns taken, kills, gold, and precisely what killed you. It also tracks your total runs, wins and deepest descent ever. It's stored on your device only.
Can I change how it looks and feels?
Settings has an animation speed control — Slow, Normal, Fast or Instant — plus switches for screen shake, damage numbers, haptics and sound effects. Turning screen shake off is the one to reach for if motion bothers you. Animation speed and sound apply from your next run.
When does it come out, and how much will it cost?
Undertow Explorer is still in development and doesn't have a release date or a price yet. It'll be a one-time purchase on the App Store when it's ready. Email us if you'd like a nudge when it lands.
I found a bug, or I have an idea.
Please send it to support@portsideshirts.com. If it's a bug, the seed and class from your run are the single most useful things you can include — they let us replay the exact wreck you saw. See the support page for the rest.