It's been a few weeks on and off over the course of some months now... this kind of thing is impossible with the original game engine, so this is using the GZDOOM engine with some high-resolution textures and model packs for Heretic, plus some sprites I whipped up myself (mainly decorations and NPCs). Stuff like this takes awhile, especially to do it right, and since this is a lot more advanced than your typical classic first-person shooter, it's taken even longer than usual just to get to this point.
It's required
tons of ACS scripting, and almost every object in the game is custom using DECORATE definitions. The "bridge over water" isn't possible in most source ports, so GZDOOM is required for that, plus for the dynamic lights that are used all over the place. In the dungeons, the rooms are rather dark, so I created a dynamic light that follows the player. Boom bombs work differently... you toss them and they explode on impact (they will blow your ass up too so you gotta watch it) but they still blow up walls (this required a LOT of special tricks). They're also considered a weapon here rather than an option. The fire wand works roughly the same as in the base game so far... but I've only added the short-distance fireball attack for now.
I've only added two monsters for now... the slime and the dragon boss. Slimes are more aggressive here than they are in the original game, and the dragon boss isn't so predictable anymore. It still shoots four fireballs at you, but the time isn't finite anymore, and it also has a "low health" attack where it spits tons of fireballs in desperation. I didn't have any other dragon sprite sets so I just reused the sprites from the original game, though its fireballs are from something else.
And then there's the maps... there's 18 of them in total. The Shrine has its own map, then each sphere has a map, then all the houses for each sphere share a map, then each crypt has its own map, and then there's a map for the final battle in the frozen north. The Shrine is the most complete so far... I've not put in the stairways to the other spheres, just the front door. The Land Sphere has about 80% of its geometry mapped so far, but only one "screen" has a moving rock event (where you get the fire wand, of course).
So yeah... plenty left to do.
It would be years to bring this to completion, and it's very low-priority since I already have other projects with much higher priority (JB and Monolith right now) but this is still a fun distraction when I can't dedicate huge amounts of time to PCE coding.