How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix a Pygame Platformer Tunneling Through the Floor When Falling Fast

Q: What causes a Pygame platformer tunneling through the floor when falling fast?

Gravity makes the player's per-frame displacement larger than the floor's thickness, so the rect is below the floor before the overlap test runs and no collision is detected.

Quick answer: Cap fall speed, sweep the movement in sub-steps and test collision at each step, or check the swept rect spanning old and new positions.

At high fall speed your character drops straight through the platform. The frame's vertical move exceeds the floor thickness so collidepoint/colliderect never overlaps. Sweeping the motion in steps catches the floor.

How to fix it

1. Sub-step the movement

Move the player in several small increments per frame, testing colliderect after each, so a single large fall step cannot skip over the floor.

2. Cap the fall speed

Clamp vertical velocity to a terminal value smaller than the thinnest collider you must hit, ensuring per-frame displacement can never exceed a floor's height.

3. Test a swept rect

Build a rect that spans the player's old and new Y positions and test that against floors, so a fast pass-through is detected as an overlap of the swept area.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Pygame error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

The bug you can't reproduce isn't gone — it's just invisible until you capture it from the player's device.