Descriptive Problem Summary:

Particles are now flickering based on the FPS.I don't know if this is intentional but they now look pretty bad unless the fps is at least 60fps.
Here's a gif recorded at 60fps while the world.fps was 20fps: https://i.imgur.com/6C8DO1r.gif

Numbered Steps to Reproduce Problem:
Create particles.
Observe.

Code Snippet (if applicable) to Reproduce Problem:

The snippets from the DM Reference are enough to test this,but I'll include a demo anyway.

https://www.mediafire.com/file/bgav9qdudnfej19/ ParticlesDemo_src.zip/file

Expected Results:

Particles be displayed smoothly regardless of the FPS,like they used to be in version 514.

Actual Results:

Bad particles rendering.

Does the problem occur Every time:
Yes

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)
It didn't occur in the stable 514 version and it has occured in every 515 build that I've checked.

Workarounds:
Increase the fps(world) or fps(client).