Doesn't seem as good as the original
While on it's own this follow-up in the 'Death Mansion' series is alright, it suffers from sequelness: IMO it isn't as good as I thought the original was. The big thing that stuck with me was that the music didn't seem to fit with the action and that it didn't feel as fast-paced as your original.
The graphics were a slight improvement over the original and the plot fitted well though with Part 1, but it was a bit of a tease given how little was revealed; though you've said that you're moving out of stick animation with your next work, so all's forgiven for now given I suspect you'll probably give the viewer more in the next addition to the series. :)
I said it before and I'll say it again: keep working on this series. I'm interested to see how it pans out and finishes.