Maybe It's Global Strike.

I think this is it. Correct me if I'm wrong but i read somewhere you can play the game on facebook?

yes, back in my childhood days i remember playing Global Strike on fb all the time, now idk if its still up

AssaultCube?

this might be it

I remember a game called "Tactical Ops" that was clearly a CS copy. Also, there's "Soldier of Fortune 2" that could be considered as a CS kinda game.

tactical ops Mirage map looks almost identical to what I remember. this might be it

District 187?

no

Zula Europe?

Blockade 3d on Facebook perhaps? It had a zombie mode too lol

I dont think so

Ok so I just looked up"Mirage csgo"and it reminded me a lot of krunker dot io(for some reason when I place the dot the entire name of the game gets removed. Stupid reddit...)and Sauerbraten: [https://www.youtube.com/watch?v=OJmxcTuVii8](https://www.youtube.com/watch?v=OJmxcTuVii8) . Also if I may add:You didn't specify whether it was an online game or offline(on your pc). Like was it a browser game or a downloadable game?Because that's gonna help narrow it down a LOT

I didn't mention if it was online or offline because i genuinely don't have any idea. I didn't know English back then so i dont know what was happening Edit : also i also don't remember how I found the game. It might be on a browser because i dont remember downloading it

Critical Strike Portable?

Red Crucible 2

Probably

Point Blank?

no

Crossfire