Around 1 hour 6 minutes to complete all 3 missions. I believe each mission is basically the next difficulty up with only slight variations in enemy arrangements and a few different rooms on each one. Same bosses and general layout with a re-skin of the Chef boss. Beating any of the 3 missions can probably be considered completing the game but I went through all of them anyway. You only get 4 continues for the final mission. Im not sure what is adjustable in settings since I cant read japanese. You get 9 credits for the second mission and maybe more for the first mission. The only thing that was considerably harder about mission 3 was the 4 credits. Gameplay wise I didnt notice anything drastic. This is unedited since I never ran out of credits in any of the 3 missions. The third mission was close though. You get end credits after each mission. This is the sequel to Dynamite Cop (Die Hard Arcade) released only in Japan. Good game. Very easy kill.