If you are comparing Ready or Not to this game I would say Ready or Not is more SWAT style. GB is more like Ghost Recon style. RoN has civilians and hostile AI and is only Coop. RoN also has smaller confined maps with max 5 players with 6 coming in the new patch. This game Ground Branch has been out much longer then RoN. There are no civilians and you can have a lot of players like 15+. GB maps are much bigger in scale. GB also have PVP which RoN does not. The guns feel the same as RoN. GB has the best weapon customization in any game I played so far. You can add rails, multiple sights, multiple lasers and a flash light. You can customize your gear down to the vest, belt, boots, and gloves. Pick the colors you want for the clothing and add attachments to the helmet like Night Vision and strobe lights. You have way more tons of customization not just to the weapons but to the AI aswell. They give you sliders for every single AI behavior so you can adjust the AI exactly how you want. You can play day maps and night maps. I would say tho RoN AI is a bit better. But I will also say RoN AI is more predictable then GB. The AI in GB I have not figured out. Sometimes they push where they last heard something or saw something then just stand there. Sometimes if they know exactly where you are they will flank and move to your location. If you kill 1 enemy, suddenly 4-5 enemies will come out the wood work to investigate the sound if it was near by. In RoN its a lot of rooms, doors, rooms and doors. Where GB is more open, some buildings have doors and some dont. Most maps you can just pick off half the population of enemies out in the open and if you miss your shot they do run. but sometimes they just run left, stop then run right, stop then run left, stop. You get the picture.
There are also WAY more guns in GB then RoN but RoN has riot shields and tasers and pepper spray and more tactical stuff. Also in GB its only kill on sight where RoN you want to try at least to make the enemy surrender.
The graphics are much better in RoN compared to GB,
Last but not least, I think match making in RoN is a bit better with smaller team and you can hop in and out easy. GB there is a list just like BF or COD and you choose which game you want to join. The game in GB is map locked until people vote for a new map. You can jump in the game any time in GB even when people are still finishing the mission. You can chill in the lobby and shoot at the fire range or adjust your gear, or you can spectate the players still in the mission and watch. Then when that game ends, people can que up at the map and join the next game.

Honestly both games have their own pros and cons. They are both worth having in your library.

Zero Hour is going to my next purchase most likely. With all 3 games in your library you should have 100's of hours of fun.

If you are comparing Ready or Not to this game I would say Ready or Not is more SWAT style. GB is more like Ghost Recon style. RoN has civilians and hostile AI and is only Coop. RoN also has smaller confined maps with max 5 players with 6 coming in the new patch. This game Ground Branch has been out much longer then RoN. There are no civilians and you can have a lot of players like 15+. GB maps are much bigger in scale. GB also have PVP which RoN does not. The guns feel the same as RoN. GB has the best weapon customization in any game I played so far. You can add rails, multiple sights, multiple lasers and a flash light. You can customize your gear down to the vest, belt, boots, and gloves. Pick the colors you want for the clothing and add attachments to the helmet like Night Vision and strobe lights. You have way more tons of customization not just to the weapons but to the AI aswell. They give you sliders for every single AI behavior so you can adjust the AI exactly how you want. You can play day maps and night maps. I would say tho RoN AI is a bit better. But I will also say RoN AI is more predictable then GB. The AI in GB I have not figured out. Sometimes they push where they last heard something or saw something then just stand there. Sometimes if they know exactly where you are they will flank and move to your location. If you kill 1 enemy, suddenly 4-5 enemies will come out the wood work to investigate the sound if it was near by. In RoN its a lot of rooms, doors, rooms and doors. Where GB is more open, some buildings have doors and some dont. Most maps you can just pick off half the population of enemies out in the open and if you miss your shot they do run. but sometimes they just run left, stop then run right, stop then run left, stop. You get the picture. There are also WAY more guns in GB then RoN but RoN has riot shields and tasers and pepper spray and more tactical stuff. Also in GB its only kill on sight where RoN you want to try at least to make the enemy surrender. The graphics are much better in RoN compared to GB, Last but not least, I think match making in RoN is a bit better with smaller team and you can hop in and out easy. GB there is a list just like BF or COD and you choose which game you want to join. The game in GB is map locked until people vote for a new map. You can jump in the game any time in GB even when people are still finishing the mission. You can chill in the lobby and shoot at the fire range or adjust your gear, or you can spectate the players still in the mission and watch. Then when that game ends, people can que up at the map and join the next game. Honestly both games have their own pros and cons. They are both worth having in your library. Zero Hour is going to my next purchase most likely. With all 3 games in your library you should have 100's of hours of fun.