Portugues
Hydroacoustic
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About the game
You are in a submarine in total darkness. The round window of the dashboard is black, and the only thing that draws anything on it is your sonar: a green beam sweeps around, and wherever it touches a wall, a mine or an enemy submarine it leaves a glowing dot. Walls show up green, mines and enemies show up red, and the dots fade a moment after the beam has passed. Your goal is a marked point somewhere in the cave, and you have to get there with nothing but those dots to guide you.
The sonar is also the danger. Enemy submarines cannot see you until your beam touches them, and then they know exactly where you are and fire torpedoes, aiming ahead of your movement. The game's own hint says it best: the best way to become invisible is to go blind. So you switch the sonar on for a quick look, switch it off and move, then ping again.
It was made in 48 hours for the Ludum Dare 59 theme "Signal", and its idea is the whole point: a control panel with chunky switches, a dark screen and the nervous rhythm of listening, moving and listening again. It starts with a short text intro and a counter at the top of the dashboard.
Playing it here
Click Play and wait for the game to load (about 10 MB, downloaded only when you press the button). The intro texts play by themselves; when the dashboard appears, use the mouse. The game has no save and a run is short. Sound effects and the engine sound are part of the atmosphere, so headphones help.
Controls
| Input | Action |
|---|---|
| Click the SONAR switch | switch the sonar on or off |
| Click the MODE switch | switch between the normal view and a wide, long-range view |
| Click the up / down buttons | speed up / slow down the submarine (a bar next to them shows the speed) |
| Click the left / right buttons | turn the submarine (a bar shows how fast it is turning) |
Tips
Ping, then hide. Enemies only learn your position when the sonar touches them. Switch it on, read the dots and switch it off again before they can shoot.
Use the wide mode to plan. The MODE switch zooms the view out and stretches the beam, so you see farther, at the price of a slower sweep.
Mind your speed. The submarine keeps moving at the speed you set, so slow down before tight turns. A hit stops you, switches the sonar off and flashes the screen.
Watch the counter. The number at the top of the dashboard is the distance to the objective; the run ends when you reach it.
FAQ
Can I play with the keyboard? No. The controls are the on-screen switches and buttons, which you click with the mouse.
Is there a gamepad? No.
Is it free to share? Yes. The code and assets are under the MIT licence.
Credits and licence
Hydroacoustic was made by TrapRu for Ludum Dare 59 and is released under the MIT licence; the author made it with Godot, bfxr and Photoshop. The fonts are three Google Fonts under the SIL Open Font License 1.1: Sixtyfour Convergence (The Sixtyfour Convergence Project Authors), Bitcount Grid Double (The Bitcount Project Authors) and Rubik Storm (The Rubik Filtered Project Authors). It runs on Godot Engine 4.6, also under the MIT licence (this build is exported with Godot 4.7.2). The licence texts, the notices of the libraries inside the Godot engine and the source of this build are linked from this page. The game was not changed; only the author's own web export folder was left out of the source.