Deep Sea Descent
Swim a koi down through the rocks for as long as your nerve holds.
- Type
- Arcade, one button
- Players
- One player
- Ages
- All ages
- A go takes
- Under a minute a go, and then one more go
- Added
- June 2025
- Last updated
- October 2026
What Deep Sea Descent is
Deep Sea Descent is a one button arcade game. You are a koi swimming through gaps in the rock, and gravity is always pulling you down. Each press is one flick of the tail that pushes you up; the rest of the time you are sinking. Clear a gap and you score, hit a rock or the seabed and the run is over.
The rocks come at a fixed spacing, and the game speeds up a little with every gap you clear, so a long run gets genuinely hard rather than just long. The game fills the whole browser window and plays the same on a phone as on a laptop, because it only has one input.
It is the game on the site people open for one quick go and then put twenty minutes into. The instructions can be collapsed once you have read them, and your best score is kept on your device.
Screenshots
How to play
- Press Space, or click or tap the water, to make the koi swim up.
- Do nothing and the koi sinks. Timing the gaps is the whole game.
- Line up with the gap before you reach it, not as you arrive.
- A rock, a cap or the seabed ends the run. Press again to start the next one.
Controls
| Key | What it does |
|---|---|
| Space, W or Up | Swim up |
| Click or tap | Swim up |
On a phone or tablet: Tap anywhere on the water. That is the only control, so the phone version loses nothing.
Tips
- Small, frequent taps beat big ones. Holding height steady is easier than recovering from a dive.
- Aim for the middle of a gap, because the rock caps stick out further than they look.
- Look at the next gap, not the one you are in.
- When the speed climbs, tap earlier rather than harder.
Questions
Is my best score kept?
Yes, in your browser on the device you play on.
Why does an ad sometimes appear between games?
There is an optional ad break after a number of games, which is how the site pays its hosting. It never interrupts a run.
Nothing in this game costs money, and there is no account to make. See the parents' guide for what is in it, or the privacy policy for what we store (almost nothing).
More games
- Fleeced! — Run a prison bakery staffed by sheep, and find out who the business really pays.
- ROC City — Shake down Rochester, open the rackets and take the city from the East Side crew.
- Hell's Kitchen — Eight chefs, one kitchen, and only one of them is walking out.
- See all games