Actually, it can be used in arcade with no problem. But you'll have to be patient when you're doing the missions. Also, be careful on your ammo. You get only a certain number of bullets, so infinite ammo won't work. You'll only be able to use a combination of Inf Sp + Heal (f) . Those are enough to help you. Also, you can use 1 hit - kill to destroy all the bosses. But be careful. Use that only after you do some damage to them, or you'll get kicked. Also, do not use 1 hit - kill when you have to protect somebody. It's weird, but the 1 hit thing also applies to the enemy, which means that they can also kill you or the ones you have to protect with one shot. Good luck!