I haven’t played any Ace Combat games, so I couldn’t tell you how different this game is.
When you are in your fighter jet, you mainly use missiles to take enemies down. You lock on, press B. When you get in behind enemies you can press LB + RB to enter chase mode where you have better accuracy and it has a zoomed in, cinematic, chase camera. Some of these are scripted; so you chase a plane close to the ground, and weave in and out of structures. The missions take part in real world locations, which is a nice touch.
Maybe it's a weird complaint because most games are like this - but it seems repetitive. You shoot a wave of enemies, another wave appears, then another wave appears. There doesn’t seem to be any variety to the tactics, it’s just rinse and repeat.
Luckily the game does vary between levels, but I think the problem is that each mission overstay’s its welcome. I often played just one or two missions in each gaming session, because it became tedious or tiresome.
Some missions you control a helicopter. You can still do a roll to dodge missiles, still gunning targets and using loads of missiles. It’s just slower, played at low altitude, and you can hover in place.
Some missions are on rails, so you are the machine gunner in a helicopter. It’s the usual Call Of Duty style stuff, gunning soldiers, rocket launchers on the roof, stopping helicopters taking off, destroying vehicles to aid ground troops.
There is one stealth mission where you have to navigate through search towers, then do some bombing runs.
Assault Horizon isn’t a terrible game, but it always feels repetitive and low skilled. I just felt I was doing the same thing repeatedly, then when the mission changed; I was doing some other thing repeatedly.