The waiting widow?
I'd like to check the release notes to see if something was changed about that enemy, but the release notes site thing is glitching or something, because all I get is "OMG SO YOU WANNA DOWNLOAD INDEX.PHP? OKAY I DONT NEED AN ANSWER I'LL JUST DO IT FOR YOU" when trying to load it.
Considering that you said "huge bullet made of bullets" though, I think you might be talking about the Arc instead, which uses the same art as the Widows for now.
The Arc is designed for a super-direct assault; as such, simply strafing all over the place when it's around basically shuts the thing down. And like all enemies, it's not exactly the brightest bulb, and absolutely will happily shove it's own attacks into a wall, instead of firing those shots down a tunnel, you can use this to get it to angle it's shots a bit, and then pop out, fire at it, and dive back behind something. This enemy though is most easily defeated in the open. One thing I might do is change up it's actual movement pattern though, so that if encountered in a tunnel, instead of waiting for it to bounce around like a moron for 20 years so the thing eventually does get "out in the open", it'll simply come after you after waking. That might be a good change and would fit the "direct assault" idea better. So I think I'll do that.
Other than that, note that each individual attack it uses does not form instantly; it fires a single bullet, which waits a moment before "expanding" into that one huge bolt.
Aside from altering it's AI choice and such, I might alter the shot speed a bit, but other than that, no intended changes for now.
Note though that it's not meant to be an early-game enemy. Probably the Widows wont appear in the super early game either. The early floors are meant to be not at all too threatening, but right now, almost none of that is set up. There's like, what, THREE enemies, I think, that are gated by floor right now? I think it's three. All of the others just appear whenever.
So, theoretically, when you encounter things like the Arc in the full game, you'll have gotten a variety of powerups and such by then to even the odds a bit. But for now... well, the odds are a little funky, heh.