And Shadow Operations Unit DLC for first game too, so it is not that Complete as they say

As for me most important DLC for grindy achievements, and a lot of fun.
Yeah, this can definitely be confusing. I mean not this particular case (because you guys already covered it), but in general.
Digression:
Beat Hazard - Shadow Operations Unit was release on Steam on 17 April 2014.
The
Beat Hazard Complete license package was released before that (in 2013) and removed from Steam's game page on the same day SOU was released.
From the publishers perspective this was probably a clear transition.
The no longer "complete" license package was removed from Steam and replaced with a different one: the
Beat Hazard Mega Bundle (which included SOU).
What they didn't account for, however, was that those Beat Hazard Complete keys would be circulating the marked for years to come (over 7 years and counting), confusing potential buyers.
And BTW: the Beat Hazard Mega Bundle got superseded yet again (in May 2018), by the
Beat Hazard Epic Bundle - which is an actual Steam bundle, not a Steam license package.
It might not be a big deal in context of what we do here (especially as everyone is readily helping everyone to solve those riddles), but many bargain key vendors often advertise their stock with those decommissioned license package names - without even giving proper description of what they contain. And again, this might not be a big problem for those who know to triple check everything on SteamDB, but it's confusing nonetheless.
Oh, and to raise the difficulty, the person who holds the particular key can't even check what it's for without activating it - even if he knows how!
The only way this can be done is if the key holder already own the particular game on his account.