Most task resolution in Cryptworld is handed with simple roll-under percentile rolls made against your basic attributes. However, there are times--mostly combat, certain skills, and fear checks--where things get a little more complicated and cumbersome. These special checks are percentile rolls as normal, but then you need to find the margin of success by subtracting the number rolled from the ability score or skill in question; that result is then cross-referenced against the following extremely 80s chart:
Combat in Cryptworld deserves a few notes. Weapon damage is entirely dependent on skill and the result found on the chart above. A screwdriver is as handy a weapon as a Luger, more or less. (Though having more skill with a handgun will let you fire it more than once, but again that makes the damage dependent on skill and not the weapon in question.) In general, Cryptworld focuses far too much on detailed rules for combat and on specific edge-case combat skills. Again, this is likely the residue of the hobby's wargame roots.
One particularly egregious wargame-y aspect of the game is how it handles initiative. It looks simple at first; each "side" in a conflict rolls a d10 to see who goes first, but it's all uphill from there because once you've established the sides, they take their actions according to this absolutely bonkers "order of operations":
Side A uses their Paranormal Talents
Side A makes their Missile Attacks
Side A Moves
Side B makes their Missile Attacks
Side A makes their Melee Attacks
Side B uses their Paranormal talents
Side B makes their Missile Attacks
Side B Moves
Side A makes more Missile Attacks
Side B makes their Melee Attacks
At the start of a new round, you roll for initiative and do the above all over again. I find that practically unfeasible.
Amusingly, there is a "Penetration Bonus" derived attribute that only applies to melee attacks made against armored foes, which doesn't really feel like something that will come up all that often in a game that is either trying to emulate Hammer Horror or 80s slasher flicks. But it's there because the hobby hadn't really freed itself from the specificity required by the wargames of Chill's era.
Cryptworld also has an extremely idiosyncratic approach to skills. Characters tend to have few skills, which differentiates the game from skill-focused percentile horror games such as Call of Cthulhu, but the skill list is quite strange. Some skills you expect, such as Investigation or Stealth, but most of the list feels oddly specific given what isn't there. There are no Persuasion or Deception skills, as those are basic rolls against the Personality attribute, but Mounted Melee and Bullwhip are detailed as skills your character might have--which seems far-fetched given the "modern horror investigators" theme of the game.
There is an option in Cryptworld to give your characters Paranormal Talents, the kind of psychic powers most often found in horror stories. These are all well chosen and seem fairly well defined. Using them successfully is never certain, and the attempt to do so temporarily costs a character some of their Willpower.
However, Cryptworld is also one of those retroclones that preserves both the system of an older game and its haphazard organization. Cryptworld is not an easy game to navigate, despite its short page count. As an example, there are three hit point-like attributes you need to track for every character: Current Stamina, Wounds, and Current Willpower. The rules for regaining Current Stamina and Wounds are both found in the combat chapter, but the rules for recovering Current Willpower is buried without a heading in the Paranormal Talents chapter. In a cleaner, better organized game, the rules for all three would be found in a "Recovery" section. An index would also be helpful here, but alas, we do not get one.
There is a good chance that most of the above critique sounds unrelentingly negative. I do think that by modern standards Cryptworld is clunky, overwritten, and often clumsy, but that doesn't preclude it from being fun. Take this with a grain of salt as I've only run it once, but my group had a great time with it because we leaned in to the creaky, olde timey feel of the game. Any roll that needs to reference the Action Table absolutely did slow the game down, but we treated these moments as an event. We absolutely rejected the game's proposed initiative system and just rolled a d10 to see which side got their turn first because refusing to use the rules as written is a tried and true part of the hobby's early days.
And honestly, there is a special kind of symbiotic beauty in using a tottering, aged system for throwback genres like 80s-inspired slasher flicks. If you're feeling nostalgic or treat the game as a bit of schlocky kitsch, Cryptworld finds its niche.