Yes, I prefer to have Zargon as a human player and I enjoy taking the role myself, but this was a fun experiment to come up with a system that doesn't require a smart device (and rely upon those who maintain it to create the quests I get to use on it).
I picked a basic quest layout to serve as the skeleton... "The Maze" from the 1st EU edition HQ with the monsters removed and everything else put out right from the start (just as in Space Crusade you can see all the doors and rooms right away, just not the monsters since their true identity is hidden until they come into Line of Sight). The monsters (and furniture) are generated by playing the tiles which are revealed once they enter hero LOS.
Instead of earning points from killing the aliens (a la Space Crusade), these monster tokens carry gold values (inspired by the Japanese Game System that puts bounties on all monsters except wandering monsters). Some of the tiles aren't monsters but are furniture (no gold value), or opportunities to draw an Equipment, Potion or Spell Scroll card or it might be a harmless rat! There are enough monster distributions that you could make sure of one or both of Kellar's Keep and Return of the Witch Lord or just the game system. You could also make new tokens to correspond to the new monsters in other expansion but I haven't made any of those yet. Since I'm using the map tokens (like HeroScribe uses) they're very quick to make and instantly recognizable. You could make a set matching the style of the Remake easily enough but I prefer classic.
Shadows (all the unrevealed tiles) can each open doors and move up to 5 squares at a time. Once revealed, they have their normal movement (if any is left) and can attack any good guys within range. Furniture that appears in a corridor or in front of a door is instantly destroyed (removed from the board) and their position is adjusted if they need to make room for another figure (similar to how the big Dreadnought behaves in Space Crusade which there takes up 4 squares but is hidden under a blip that is only one square).
Monsters should go straight for the nearest Hero (similar to the dumb brute AI of the Companion App I suppose), though without this I guess a player could be decided by dice roll to move the monsters, and settle old grudges or something, but this is probably more "fair." In the case of more than one Hero being equidistant from a monster, roll a red die for each Hero. The lowest roll is the one attacked (in cases of a tie, re-roll until one has lower). I suppose if Mercenaries were added, they would be treated the same way as heroes for enemy targeting purposes. Someone told me that the Companion app now has monsters target the hero with the highest body points, if you are more in the mood for fairness (or to lower the difficulty) you could implement that behavior instead I suppose.
The Center Room is divided up by quadrant, so you can either put one tile in there or else leave it empty. The Spiral Staircase is seen from the beginning, so this can be your escape out of the quest. But quit early (before all the monsters have been cleared from all four quadrants including any Wandering Monsters) and no additional reward is given! (suggestion: 500 gold, although less or more depending upon the difficulty perhaps!)
The Wandering Monster is a random draw from the Monster card deck to determine it for the rest of the quest. Wandering Monsters don't give gold bounties like the others. To make it somewhat fair I first removed the Gargoyle card before drawing the Wandering Monster.
The only thing missing is searching for secret doors! (I just placed them out at the start) Another thing you'll notice is that you run out of closed doors, but this is no problem since Shadows can open them anyway (but revealed monsters cannot) and doors can't be closed.
I printed out something like 112 Shadow Tiles (glued them to chipboard) and you can decide how many you want to place. I found that 16 "Shadow" tiles per board quadrant was pretty hard with basic heroes (I actually gave them a Battle Axe, Longsword, Crossbow and Staff and they still got TPK!). Using 8 tiles, cutting the total in half was not very hard at all. So probably 10-12 tiles per quad is the sweet spot for medium difficulty.
I used the Combat Cards, Evil Wizard Deck and a couple of extra cards in the Treasure Deck as well. See the attached file. Feedback is welcome! I did some live playtests on twitch also.
Watch my second attempt here (Introduction) and the longplay using the Remake (coming soon).
First attempt (using the classic set): here. "Hard" mode!
The file below contains images of all the tiles, ready to print (they will print out slightly smaller than the HeroQuest Tiles, which is on purpose, scale them up 10% or more if you want them larger) along with the rules and suggestions on how to use them to play solo quest (or HeroQuest with the physical game and no specific Zargon player).
