Sine Mora (Latin for "without delay") is a 2.5D horizontally side-scrolling shooter. The ship's movement is limited to two axes, but the camera sweeps and the different layers show the environment and objects are rendered in 3D. The game has a dieselpunk theme with robots and floating machinery. The player controls Argus Pytel's ship. He is part of a team of partisan pilots who determine to infiltrate Syriad, a floating fortress that guards the planet. They are after antagonist Ronotra Koss who has smuggled robots and kidnapped a girl of great importance.
The game is played as a bullet hell shooter where the screen is flooded with enemies and bullets. It is however more forgiving as the standard health mechanic is replaced by a timer that counts down. Each hit drains the timer further, while shooting down opponents extends it. The goal is to reach the end of different sections before time is up. The environments do not only include air events, but are also set underwater. Typically the end part of a level holds a giant boss with strong attacks. The ship has a primary weapon and can collect different powerful sub weapons with limited ammo. Shooting with the primary weapon builds up a score multiplier while the sub weapon resets it. Defeated ships leave behind power-up tokens such as time extension, sub weapon, score bonus, and shield. There are also tokens to upgrade the primary weapon's firepower in up to 9 steps. These upgrades are permanent, but each time the ship is hit a red upgrade token is dropped and it needs to be collected again before it disappears. Additionally a time capsule can be activated to temporarily slow down time in the environment. The player's ship can still move and shoot at regular speed and it becomes easier to navigate through a cloud of bullets.
The game modes include Story, Arcade, and Score Attack. At the beginning of the game there are two difficulty levels, but during gameplay sometimes an easy or a more difficult route can be chosen as well.
Initially it was announced as a game for the PlayStation 3 as well, but in December 2011 the companies announced that it would become exclusive to the Xbox 360. After the release it was eventually opened up for a release on more platforms. In November 2012 it was made available for PC, PlayStation 3 and PlayStation Vita.