While i do not think this game deserves a 5.5, i do think the df rails are overboard; a disable option would solve this.

User Rating: 8 | Ace Combat: Assault Horizon X360
Granted, there is an option to turn off flight assist, and the original controls are available, however, this game would be a 9.5(imo) if you could completely disable the rails in df mode. This should not be a deal-breaker for fans of the series since using df mode is not required. I think the df mode general challenge level is acceptable if flight assist is turned off because you do have to use the flight controls to track your target. If you get too far off your target the df will cancel. I would say that the most difficult aspect of the game is maneuvering your jet to attack line or df initiate angle...them migs 'er fast! The game looks and runs amazing. I am keeping my review short as i have only put a few hours into my game; just wanted to say that the df mode is not as lame as gamespot says it is. Tweak some options and Turn the difficulty up to maximum and enjoy!