Modiphius adapted the 2d20 system to different settings in slightly different ways, but the basics are the same.
Your character has six characteristics (Cunning, Might, Passion, Empathy...) and for each test you have to pick the two of them that make more sense in that context (for some tasks, like attacking in a melee or ranged attacks, etc. you may have already that indications by the book, but for other tasks you can make up our mind on which two are the most relevant and if they make sense it will be easy to agree that with the GM. Then you roll 2d20 and you have to roll under your characteristics. If your dice was under the lower characteristic you get one success, if the roll was under the sum of your characteristics you get another success, etc. then you add the successes of both dices (and of the potential additional dices that you may be able to roll) and, depending on the difficulty of the task, you need to check if you had enough successes to pass or not.
In general the basis of this ruleset is quite a nice system, very flexible and open to creativity.
The problems (in other 2d20 settings by Modiphius) are that sometimes the rulebook is very thick and it is not easy finding what you want when you want, and sometimes character generation has some gaps in describing some option (maybe there are too many, or too fancy, options and some detail is not described). On top of this, the full combat rules are a bit too crunchy for somebody (they involve also momentum and threat and other kind of game mechanics), making fighting a bit too long and mechanical (as crunchy rulesets usually do).
Maybe for managing these issues, Modiphius progressively modified and (in general) simplified the generic 2d20 ruleset in time, when applying it to new settings.
Hopefully on this occasion they will find the perfect balance and the most suitable adaptations to this specific setting, that is very interesting and full of roleplaying possibilities.