We've launched the "Double Trouble Pack," a Steam sale that includes both "Slay the Dragon! The Fire-Breathing Tyrant Meets Her Match!" as well as "Dark Waters: Gino and the Witch of the Black Swamp." Buy them collectively and you'll get them at a nice 20% off.
https://store.steampowered.com/bundle/40771/DoubleTrouble_Pack/
There's no particular reason to scoop them up at the same time, though you may find that each title poses and answers some questions about the other...
If you enjoyed "Dark Waters," we're confident you'll love our new monster girl eroge with a similar (but less brutal) dark twist.