Given the damage- or lack thereof- to the targets, I'm fairly certain it has less muzzle energy than a .22 Short, and the presumed absence of rifling should render it pretty inaccurate at ranges farther than across the room. (I say "presumed absence" because I can't make out any rifling marks on the fired projectiles.)
FWIW rail guns or coil guns have been discussed on this forum before. The main technical problem is that all currently extant batteries that are small enough to carry, yet powerful enough to do real damage, are arguably much more dangerous to the shooter than to the intended target.
The main reason these things have primarily been investigated as naval weapons is that warships usually come with a massive built-in power supply already.
It's still nifty though.
