Mighty No. 9

First, since you should be playing on normal, go into the options and set the number of lives to 9. This will give you more chances. The City and Prison bosses are automatic for this.

You must defeat all the bosses at the end of each level. Mini-bosses do not count. Trinity the final boss counts as two separate bosses, but in order to complete the achievement you must kill both forms with the normal attack in the same run.

Pyro: You want to jump over him for most of the fight unless he yells "crush" then you just want to dash underneath him. For the second phase you need to not get hit as remember this move is a one hit kill.

Cyro: Just keep dashing until he forms the pillar, then spam the normal attack to drop him down and injure him. If you stand back you only need to worry about bouncing attacks if he uses them. For the second part you want to dash underneath the his blast when is shoots up, then wait for him to form the pillar and do as before.

Electric lady: I just spammed the normal attack at her and dodged her and the little spikes. I did get hit a few times when she used her attack but it wasn't a problem.

Seismic: When he goes to one side you want to jump up the opposite wall and then dash until you are over him. This will dodge the extendo arms attack. When he dashes, you cannot really do much damage as you can only attack him from behind. I found the most damage is dealt when smashes the ground. Find the opening and then spam him with normal attacks.

Battalion: you want to spam your attack. When he couches to attack you just jump and dash behind him and continue attacking. If he is against the wall you can dash under the normal lemon shots or jump and dash above the missiles. If you are fast enough he won't be able detonate his bomb. If he does just stand on the opposite side of the screen and continue attacking.

Avi: When he swoops down you want to be standing on the platform opposite of the little eye bot and just spam the shot at the eye bot. When he is dropping bombs I would stand in the center and if he dropped bombs there dash to grab the side platform and then return to the center after the bombs explode. When he goes up and down on the screen I just ledge grabbed the center platform on the opposite side. This is a long fight but no very hard.

Brand: You need to just spam your attack and stay about have the stage away from him so you have time to jump over his spin attack. When he jumps I generally just dash underneath him and then turn and continue attacking. For his super, try your best to dodge and then continue fighting. It may help if you have a heal tank.

Shade: I fight him normally with just the normal attack but I found that just standing on the chandelier is the best place as he normally spawns up top. Just spam him and he won't be able to get a shot off. If he is down below you can drop down and dash to the wall to get behind him and not get hit. Return to center. Keep repeating. For the super just keep moving and you should be fine. I kept dashing across the screen. For the second part repeat as before but shoot the "blue" one.

Robot Factory: The robot out front is pretty easy just keep jumping and shoot his eye. when the lower arms goes across the screen jump and dash over it. When it comes at mid level crouch dash underneath it. I didn't worry too much about the other arm but you can dash back over/under the lower arm to avoid it. Keep repeating and absorb it. Go up to the platform and mash the attack to damage the boss. When the robot returns repeat. When it fires the missiles, dodge the first two waves by going all the way left and then right. For the barrage, I stayed in the center and was able to dodge everything (it will take some practice). Dodge the double hammer fist and keep shooting the eye until you can destroy it.

For the Trinity fight, I recommend having a replenish life tank for the second part of the fight. This means you essentially have one chance to do the entire fight. It took me about 8 or 9 tries to get this one.

In her first form, when she spits outs the death balls, you need to wait for one that is at your height to crouch dash underneath and then quickly to a hop to jump over the one on the ground. You can shoot her once she spits out enough of the death balls. Keep mashing and you should be able to absorb at least once. When she is raising the platforms, just get on the tallest platform and spam shots at her. When she gets close jump and dash over the top of her. Lastly, when she comes to the center of the screen, she will do a radial attack around her. I found that standing right under her is the safest place. She has always gone clockwise in her attack so I stand on the platform right below her to the right. You can then hop up to the left and spam shots at her for hopefully an absorption.

In her second form, when she forms the stacks, simply shoot the lowest stack until you can absorb it and then dash through. Repeat until only the head is left and try and do as much damage to her, remember to dash over her head to avoid damage. When she sprouts out of the ground, I stayed in the middle and quickly took out the two stacks. When she falls down, you can jump up the steps and she can no longer hurt you. When she shoots the death balls in this state there are two versions: 1. she will shoot at the highest platform and work to the middle platform (i.e. you want to stand next to her) 2. she will shoot the lowest platform and move to the middle platform (i.e. stand on the top platform). Lastly, she as the beam attack. When she starts on the wall you want to stand on the second to last pillar when they raise up. Once the first beam is clear, jump to the tallest pillar to avoid the second beam. Next jump to the second to tallest pillar again. When it starts to lower there will be a break in her beam, jump and dash through (practice the timing on this). Lastly, stand on the tallest pillar and when she fires the beam you want to wait and then dash out over it. To avoid the second beam, dash down in the gap that forms between the two beams.

Hope this helps.