The most important part of a solo game is choice. What choices as a player do we have? Are they meaningful? Let me run through Gladus Hereticus (GH).
Character creation: Completely random. You might start with terrible stats and several potions of cure disease.
Starting the game: randomly determine where you are and if you encounter anything.
Finally we have some decisions to make:
During an encounter you can choose which enemy to attack (if more than 1), to use an item, or run away. Your attacks and your enemies are resolved randomly. You can choose which statistic to use to attack (between Strength and Dexterity, but will usually be obvious until you get injured). You get 1 action, then each enemy attacks you, and then you get to choose to attack, run, or use an item. Repeat until you or they are dead, or you escape.
Outside of combat you can use items freely. You can also choose to move (drawing a random new location) or rest in the same location.
Most of these choices are pretty minor and dependant on random results. Fights are basically on auto-pilot: Hit you, hit me, hit you, hit me.
The goal of the game is to find 10 specific items. Note that finding items is random, and the item you get is random.
Let me tell you about my first experience because I think it is illustrative.
I started with a suit of powerful magical armour (13) and decent stats. I proceeded to wander a few locations before finding a Forgotten Arboretum. There I hunkered down, resting and punching the occasional monster to death. I ran through the deck over and over slowly building up experience and finding items. Only a few locations offered a better chance for loot and came with a much higher chance of encounters. It was better to remain where I was, flipping cards as I was just as likely to find items as encounter monsters. Between each fight I could usually rest several times, more than enough to completely heal. There was no incentive to go anywhere else, and then I stopped playing. Using this strategy I could probably eventually win as my armour was so strong I would only ever lose a few points of stats at a time.
On those occasions when I did lose stats it was a headache randomly determining which stat was harmed and then determining if a modifier changed. It's fiddly and awkward.
The degree of randomness hurts this game
Your stats are random, but when you level up you can raise a stat by 1. This is a very small gain, and levelling can take a long time. So you can try and kill enough monsters to get you stats in shape or start again and get a better character.
Damage is randomly assigned to 1 of your 3 stats in a fiddly bit that I found annoying to keep referring to.
You have a low chance of finding a random item. You need 10 of the rarest item to win the game. How long does this take? Actually if you find the Forgotten Crypt you get all the loot forever because the game is broken!
Flip a card for an enemy attack. Flip a card to see which stat takes damage. Flip a card to see if you are poisoned. Flip a card to see how much damage poison does to you or if it goes away. It's a lot of turning cards and doing simple mental math between each actual decision.
Broken Rules and Missing Details
Staying in 1 place to rest is allowed in the rules, and nothing compels you to leave. Thus when you reach the Forgotten Crypt you rest there until you find everything you need. I get the impression you are supposed to move all the time, but the ability to rest and still find items means realistically you should get to the best place to rest and also find items or fight monsters and remain there until you are geared up/levelled.
I also think the designer needed to specify that your starting stats are maximums. The way it is worded I initially thought I could rest and raise my stats above my starting value, as though my character began the game injured. I soon thought better of it, but I do wonder if there is a maximum, as you can potentially find unlimited strength potions. Can strength reach 16 or higher? Do you get bonus damage at such levels?
The experience table only gives experience values for monsters in the Smoldering City. Are the more dangerous monsters in the Necropolis giving the same experience for the same number value?
In the Flickering Vault there is no result for King. Is it Loot or a monster?
Once you have all 10 pieces of the Decahedron Device you have to fight a bunch of monsters in the "next area." You redraw if you only encounter 1 or less monsters, so if you end up in the Decrepit Study you redraw forever because you CAN'T encounter more than 1 monster.
Also the amount of items you can carry is based on your strength. It's entirely possible to be unable to carry 10 items, and thus be unable to carry 10 Decahedron Devices without grinding up levels and Strength Potions which can only be found as random loot.
If you are injured and your Strength drops must you drop items? If so, and you stay in the same location, can you recover them when your strength is restored?
So your stats are based on a card draw. That card draw get's translated into a number. Your actual modifier is listed in a table by card. So if you start with 10 Dex and gain 1 more Dex you now have 11 Dex which is equivalent to a Jack which is equivalent to +1. It's a needlessly complicated set of tables that could have all been combined and more easily read using Stat numbers. THEN the amount of equipment you can carry is based on STR modifier. So conceivably to determine how many items I could carry I would check the my Strength #, convert to Card value, check the table for the modifier, then compare the modifier to the Equipment Carried Table.
The Magical Jezzail ignores armour but not magic armour. I'm assuming the Fire Staff and Alchemical Grenade ignore armour (even magical) as their entries do not specify they don't.
The healing potion from the Necropolis is different from the one from the Smoldering City. The one from the Necropolis heals all your stats the value of a card draw, while the one from the Smoldering City only heals 1 stat. Are they supposed to be different? Why aren't they named differently? If they are supposed to be the same, which description is correct?
Can a monster with disease give you multiple diseases in a single encounter? Do you apply the -1 to the stat immediately? What if the stat is damaged, does it reduce your current stat as well?
When you flee an area with 2 or more monsters and get attacked once how do you determine which monster attacks? Is it random, or the strongest monster?
Random, random, random with rules that need a few more edits by the designer. There is some amusement to be had from this game, and I think the broken/fiddly bits could be fixed. You need a reason to move; a ticking clock element. The randomness needs to be toned down to accomodate the ticking clock (especially the starting conditions). There needs to be more meaningful choices for the player to make. As is I feel like I'm passively turning over cards and constantly checking tables. Regardless of starting gear the winning strategy would be the same: get to a relatively safe place and rest, fighting 1 or 2 enemies at a time, heal between fights and gather gear.