This tool is really neat already, but there are some additional features I'd love to see. I hope it's not too annoying that I'm making a thread with multiple requests, I didn't want to spam the forum.

I'd like the ability to...

• Set a delay on particle emission. For some effects, emitting one particle per frame results in too many particles. I'd like to be able to only emit particles every few frames. If an emitter is set to emit more than 1 particle per frame, I'd like those particles to all spawn on the same frame, i.e. in bursts.
• Have slower speeds. Speed "1" is pretty fast! It would be nice to go slower. I realize I can use gravity and force to slow things down, but that reduces my ability to use those for other effects. Adjusting all the other parameters and then running the rendered result at a slower frame rate could also work, but requires mathematic gymnastics and doesn't allow effective previewing D:
• Adjust the values of sliders with the keyboard (e.g. left/right arrow keys). It's very difficult to get an exact value in some of the sliders when using the mouse, and even with pixel-perfect movement some values are impossible to get (RIP gravity at 90 degrees). It's also a little easier to make small tweaks with the keyboard in general. This would probably be best with some sort of highlighting on the most-recently active slider on the current panel to make it clear what the keyboard would affect.
• Control the frame rate, either as part of the effect design process, or as a render/output setting. The default 20ms setting makes for great GIFs, but doesn't match the most common frame rate targets (30fps/33.33ms, 60fps/16.67ms, etc) or even play nicely with them. This might create inconsistency between PNG and GIF exports (e.g. at higher frame rates), but I think flexibility is more important for production use, and the user could be warned when attempting to export GIFs with inappropriate frame rates. The 1.03 patch notes include "Render FPS added", but I could not find this feature in 1.1. Was it removed with the UI rework?
• Copy+paste emitters. Sometimes, you just need two identical emitters in different locations, or two very similar emitters. It would be nice to be able to right-click on the emitter number to copy from it or paste into it, instead of manually entering the same properties for each one. This feature seems to exist in the screenshots even though it's not in 1.1, I guess it's in the works.

Bit of a long and scary list! PFXD is already very cool, but I think these features would make it awesome.

Hi eishiya, I'll go point by point.

• Set a delay on particle emission

- This is actually on our roadmap, It was in the low priority queue but I've just moved it to high for being a high requested feature. It should be added in the next update.

• Have slower speeds

- You can just right click any slider to input any value, even if the value is not between the default min/max values.

• Adjust the values of sliders with the keyboard

- That's a nice idea, you can adjust the values with the mouse wheel, but I'll add the arrow keys and WASD for my gamers fellows.

• Control the frame rate

- Yeah, it was removed with the UI rework, we forgot about it :P. We'll add it again in the next update.

• Copy+paste emitters

- As you said, this is now a feature that will come in the next update.

Thanks for all the suggestions!