I was offered a free Lumintop Worm AAA from LuckyLightBank’s Amazon store in exchange for trying and reviewing the light. They also gave me a code you can use: LLBCook8. I don’t have a tenth of the expertise of most of the reviewers here so this is a layman’s view. First some details from Lumintop:
Battery: 1x AAA Alkaline, NiMH (10440 NOT supported)
Switch: twisty Modes: 3 med-low-high (32 lm, 5 lm, 110 lm)
LED Type: Cree XP-G R5
Lens: Double-sided AR coated glass
Tailstands: yes
Reflector: Orange peel
Anodizing: HAIII
Weight: 0.42 oz (12g)
Dimensions: 2.64” (67mm) X 0.56” (14mm)
Runtimes: 36 hrs (l), 4 hrs (m), 30 min (h)
Beam Intensity: 553 CD max
Beam Distance: 47 meters max
Water Resistance: IPX-8 (2 meters)
The light comes in a nice presentation box with a lobster-claw attachment chain and two spare o-rings (sorry no pix of those but you can see them on Lumintop’s website.
Overall construction seems good, with lightly-lubed threads, a spring in the tail, and the ridged body that I assume gives the worm its name. I have usually carried keychain lights with diamond knurling or my current Olight I3S EOS’s lateral knurling, so I expected the Worm to have inferior grip, but that was not the case. The ridges give plenty of purchase, even for operating one-handed. The grooves in the head are an upgrade from earlier models, presumably to provide more grip. 
I have included a picture of the bottom of the driver but I can’t tell you anything about it and it would not screw out easily; I understand they are glued in. I don’t have any experience in taking beam shots—and probably not the right equipment—but I will say that when I look at them in the dark, the Worm beam appears to have more spill than my Olight, and is clearly brighter, as seen even in this daytime photo with both lights on high. 
There are so many AAA keychain lights in this space that it is hard for one to distinguish itself, and there is, of course a lot of price competition. My impressions are largely based on having carried Fenix keychain lights for a while and now my Olight (carrying an Arc AAA is too long ago to remember). One thing I liked is that the threads are tighter than the Olight. I find I have to periodically tighten the Olight to keep the head from falling out in my pocket but I did not have that problem with the Worm. I initially thought I would test this and review it, then stick it back in the box and go back to my Olight, but I am not so sure now. I like the brighter beam than the Olight and the tighter threads. Hmmmm.