Playing this "minigame" is a nice change of pace from time to time. There are a few different types of this challenge. Chain & Gain (my preference), Chain & Gain Limited and Special Loot Hunt and there are also as many different maps; Northcrest Manor, Moira Asylum and House of Blossoms. The last one being the easiest to run and learn, IMO. And also it's my opinion it's the most entertaining map.

So, for a category we could have a best time for reaching 5,000,000 points, which is what you need to unlock the achievement. How you would calculate that in-game is done by figuring out the base multipliers for all the "goals". Or, figure out the way you think is the best to play and see what score you get that is as close to 5,000,000 points (but not below) as possible. There are quite a few factors to take into consideration, to calculate the score.

I'm currently focused on the main game and chapters, so I don't think I'll be doing any challenge runs now, but I'm throwing this out there. If anything, to try to boost this game's popularity around here.

Light bulb...!

We could naturally make a category for collecting all the loot for specific maps. For example, House of Blossoms (Chain & Gain) has 176 loot. So we could have a fastest time for that. Whaddaya say?

"Stupify" all the guards (i.e. knock them out...) and grab all the loot. I did this some time ago (while also keeping the quick chain going). While it might not be the best guide at all, I have a video of it: