All right, it is ridiculously simple to run SWF files in your PC. At this tutorial I am using eric gurt's pb2_re34 files as the reference. Other user modification thingy is similar to follow the guide.
Step 1:
go to this link and find the button (Download/Redistribute).
Step 2:
Press "swf ~ 9.6mb" button, then you will received the download.
Step 3:
Download this thing(click me). Never download Flash player 32 as it will get your user data in order to use that thing, which is not really a good issue for normal users, so I would just download version 29.
Step 4:
Launch the flash player 29 debug edition.
Step 5:
Go to file, then open and navigate your file location.
Step 6:
Here you go~
Conclusion:
It is really that simple to run Plazma Burst 2 and other flash (swf format) games. Other modding PB2 will also be in .swf format so stay tuned.
Alternative:
If you are so dumb that can't even follow my step, here's video.