The ragdoll-like way everyone moves is really neat! The responsive dialogues are also cool and I like the difference for converted critters. The controls and physics feel like they're in a good spot, it's all quite fun as a demo! I didn't really encounter any major bugs or performance issues in the web version.
If you have plans to keep developing this project, the gameplay design seems like it can go in quite a number of ways. I think that something objective-oriented would suit the theme better than a sandbox approach. It would be cool to see the converted vampires in action and form strategies for whatever a level requires. The game has a very solid and uniquely interesting start, so I hope that you'll find time to expand it a bit after the Jam!