i‘m a terrible writer, but i guess i’ll try to give some advice anyway.
as with all things, the hardest part is getting started. so i usually i try to start with something that takes no inspiration, just work. this often is systematically writing the most dry and clear cut descriptions possible of whatever the topic is. i don't aim for any creativity or try to make the writing enjoyable to read. just boring "documentation". only do this as long as you need to though. once you have more interesting ideas to pursue (which this kind of straightforward writing often inspires), start thinking about that.
in your case, if it were me writing i'd first come up with a non-exhaustive list of games i'd like to mention, then go down that list and do the work of describing each game for someone who knows nothing about detective games, summarizing their plots, explaining mechanics, and talking about how the games differ from each other. you can think of this as writing a draft for a very boring consumer product review.
usually during this first phase i remember some of the more interesting thoughts i'd had in the past, or as i'm writing i come up with analogies i find interesting, questions i want to probe into more or stories that feel related. since this first preparation often takes more than one sitting, now that my brain has been tuned into the topic, i'll also often come up with stuff while i'm not writing, e.g. working on other things, just showering or falling asleep. all of this other stuff i write down as soon as i think of it, even if it's dumb.
often i'll still feel like i've only come up with obvious or non-starter ideas at this point, so then i'll just force myself to more deliberately come up with new ideas, by sitting at a table with a physical notepad or a word-processor open on my computer (i use like 5 different word-processors and text editors because they all have a different feel to me) and not allowing myself to do anything else. sometimes i do exercises like try to come up with 10 ideas in 30 minutes. or i try to think logically and systematically about ways to approach the article. or i just free form write whatever nonsense pops into my brain, regardless of whether or not it's related to the topic.
all of these phases don't need to be sequential. i often mix and match, punctuating them with time spent on other related activities like research. in my experience, with enough time i always end up with something i feel like i can write about. it might not be the most brilliant thing in the world, but it's at least something that is interesting in some way and i feel like i could be satisfied with.
once i have the idea i temporarily throw everything else out and focus on just that one idea until i've developed it to my satisfaction. for you this might mean writing an outline, though i'm usually satisfied with just having a general image of the intended structure in my head. then i just write. once i've gotten to this point, it's usually (not always) pretty smooth. the painful part is the brainstorming/planning and that's (hopefully) over now. usually i can move pretty quickly, integrating material i've already written with some modifications. e.g. if i get to a part where i need some boring details to support an argument or set a scene, i often already have a version of that from the first phase and i don't need to lose momentum. sometimes things go wrong and i have to change approaches. it's frustrating, but that's just part of the process.
once i end up finishing the first draft it's always a horrible mess. i honestly still don't know how to edit properly, so no advice on that. it's always really miserable for me, even worse than coming up with an idea sometimes.
this is the process that's worked for me when writing fiction, and i more or less do the same thing for non-fiction (i've been able to finally write about music in a way i'm ok with doing this), but the whole brainstorming process is way more stressful. maybe that's just because i'm less used to non-fiction.
one final quirk of how i write is that a lot of my creativity comes from deciding what *not* to write. there's two main forms of this: (1) i come up with an idea, but it feels too much like what other people would say, or (2) i have something i want to say, but i can't find a way to say it clearly or without sounding trite/boring. with (1) i might throw the idea out completely, or i'll find a way to mutate it into something too weird for anyone else to write. with (2) i might try suggesting the ideas i want to express in some indirect way. sometimes this results in stronger writing! sometimes neither of these work and i just have to come up with better ideas.
anyway, this is just me and i'm sure other people do things differently. hopefully though reading this can give you some ideas for how to proceed!