Devil May Cry 4

You have no choice but to play the levels in order until you beat them. Once you get all 20 missions done on human mode for example you can go back to any mission you want, but only on human difficulty. So pretty much you have to beat the level on the difficulty you want to play it on, and of course you have to earn the ability to play on that difficulty by beating previous difficulties first.

(human = easy difficulty, Devil Hunter = normal difficulty) The hardest difficulty ur allowed to play straight off the bat is "Devil Hunter" mode. but there's still 2 more difficulties left to unlock by beating the game on lower difficulties. also each campeign difficulty is treated seperatly. you cant play a particular level on "Human" difficulty if you haven't played the previous levels on the same difficulty. that applies even if u've beaten the game on Devil Hunter mode.

Thanks dudes. am just guna have to play them all through 1 after the other. am willing to do it for my achievements. lol.

Another question please, how do i get my health bars up to maximum and my other things as well, sorry if i sound like an idiot.

For the max health bars, you have to get all the blue orb fragments hidden in levels and in the secret mission. You will know when the secret mission is nearby when the devil bringer arm glows. You can also buy whole blue orbs at the statues and in between missions.