Gravity Trax

About the game

Gravity Trax is a physics puzzle where you place straight track blocks on a grid and adjust their tilt so a gravity-driven marble rolls from the start to the finish. Each mission is randomly one of three types: Fastest finish, Slowest without stopping, or Sync arrival, and the start and finish positions change every time. You earn a score and 1 to 3 stars, and successful runs are added to the ranking.

How to play

• Tap or click an empty cell: place a straight block (start and finish are placed automatically)
• Tap or click a placed block: change its tilt (cycles 0° → 15° → 30° → -15° → -30°)
• Turn on Delete mode and tap a block to remove it; Clear all blocks removes every track block
• Run: roll the marble / Reset: clear the simulation (your blocks stay in place)
• New mission: draw a new mission with new start and finish positions
• Works with both touch and mouse; there are no keyboard controls

Tips

• For Fastest finish, chain 30° slopes so the marble drops as directly as possible to the goal. Arriving in under 5 seconds earns 3 stars.
• For Slowest without stopping, build a zigzag of gentle 15° slopes to stretch the time. The marble must never stop for 1 second or more, and arriving after 85% of the 45-second limit earns 3 stars.
• For Sync arrival, give each of the 2 or 3 marbles a path of similar length and slope. A gap of more than 3 seconds fails, and under 0.5 seconds earns 3 stars.
• In every mission, the run ends if all marbles sit still for 1 second, which counts as not arriving, so make sure the marble never stalls on flat 0° blocks.
• Each mission limits how many blocks you can place. Reset keeps your blocks, so tweak tilts a little at a time and test again.

FAQ

Is it free? Do I need to install anything?

It is free and runs right in your web browser with no installation.

How is the score calculated?

Fastest finish rewards an earlier arrival, Slowest without stopping rewards arriving as close to the time limit as possible, and Sync arrival rewards a smaller gap between marbles, up to 1000 points. A failed mission scores 0.

Are my records saved?

Successful runs are saved as a ranking per mission type in your browser's localStorage. They will not appear if you clear browser data or use another device.

Is there a time limit?

Each run has a mission time limit (30 seconds for Fastest, 45 for Slowest, 35 for Sync). If not all marbles arrive in time, the mission fails. There is no limit on how long you take to place blocks.