Lowpass in REVERBS?

[Xaser]

I'm not much of an audio guy, so I've got a bit of a possible n00b question with REVERBS. Apologies if this is obvious to some of y'all -- I dunno what any of the options actually do or mean, and fiddling with knobs hasn't gotten me anywhere.

The Question: Is there a way to do a plain lowpass filter with REVERBS, without actually adding any echo/reverb? If so, how is this achieved?

Bonus follow-up: how would I then go about boosting bass just slightly?

Context: this is for Adventures of Square's moon levels -- I wanted to try on that classic "everything is a low rumble" effect for size when you're bounding around on the moon's surface in a near-vacuum -- so we're specifically looking for a Sound Environment sort of solution (i.e. not a global thing).

This might be a wrong-tool-for-the-job situation; I just figured it was worth an ask before diving into feature-suggestion land.