First, thank you!!! So glad you're liking HQ2. You definitely can play this using HQ2 rules. The room sequence in HQ and thus Red Death is different so I would just use HQ2 room sequences, combat and exploration rules. Red Death is pretty much a series of little dungeons plus a town to explore all of which fits nicely into HQ2 rules. Enemies in Red Death might be a little too easy for HQ2 rules so if you're finding that, consider upping their stats. Enjoy!!