In his last Patreon update, Jotego spoke about issues he was having with the Splatter House FPGA core, but it would appear he has overcome these problems to deliver a beta version, just in time for spooky season.
Here's the Patreon update:
I used to believe in Christmas miracles, now I have to believe in Halloween miracles too! Just five days ago, the JTSHOUSE core was unplayable and with completely broken music. I thought that having this beta release was a long shot, but here we are.
The main difficulty, as I explained before, has been the microcontroller (MCU). I had assumed it was based on a different CPU, and later on found that it was based on a newer model. I had to add the new instructions to this code (foreign to me). Still, the game didn't improve. Looking deeper into it, this newer CPU was running many instructions faster than the older model. Changing that was not doable in a day, but luckily there was a way around: overclocking! That finally made the game playable. So the beta core has three accurate CPUs and a fourth one, which is not cycle accurate but doing the job. Making a new design for this CPU should not be too hard, maybe a 2-week task, and it is important for other games too. I will look again into it but, for a beta, this is good to go.
Jotego adds that working on this core has "shed new light" on last week's Bubble Bobble beta core, so we should expect "several public core maintenance updates for this Friday," rather than a full update.
If you'd like to get your hands on this beta, then you'll need to signup to Jotego's Patreon.