It might be trivial but the sound mods I downloaded from here make a huge difference to the "immersion" effect in CO2. Hearing spatialized sounds really expands the battlefield as you hear mortars and RT and MG going off and echoing in the far, mid, and near distances. It really adds a 3rd dimensional depth to this stunning 2D game.
For ref only. (I actually these mods in several games just play them in the background)
https://cmmodsiii.greenasjade.net/?cat=35
For ref only. (I actually these mods in several games just play them in the background)
https://cmmodsiii.greenasjade.net/?cat=35