Not that hard for me, but it's a process I've developed over the years. I like RPGs, open worlds, exploration, space themes, things related to historical stuff I like. I like a little strategy in gameplay, some puzzl solving. I also like innovation (new ways of playing a game), and good storytelling driven games such as Detroit Become Human. I dislike multiplayer, so I always go for single player. Not a big fan of FPS, but if it's not the sole dimension of the game, I'll tolerate it.

My game selection process is quite easy though : I watch game trailers, I remember those that feel good to me. Then I look/wait for gameplay trailers, which is quite important. The more I'm excited about it, the more likely I'll buy the game.

I will exceptionally preorder a game. Otherwise, I'll look for the "Before you buy" type of reviews. If I'm still convinced, I'll buy it the day it comes out. Otherwise I'll give it some time.

My favorite game are Mass Effect series, Assassin's Creed Series, lots more also. Right now, I'm having a blast with Starfield.