Assault Android Cactus

The sole requirement you need to fulfill to get S+ is to not drop the Chain throughout the level, which implies that you have to be extremely fast in killing enemies one after the other and that you don’t have to be knocked down at all. This is very easy to accomplish in the first Zone levels but it will get dramatically frustrating from the second Zone up to the last. The fourth and fifth Zones especially will take hours and hours of repeated attempts until the game awards you with S+.

S+ ranks are mostly based on luck rather than skill: in many of the later levels you start with overpowered enemies that are hard to kill quickly with the low firepower you start with, small enemies take cover behind bigger enemies to make your Chain drop, small enemies get stuck behind walls and columns, you may pick up the Shutdown upgrade at the wrong time and freeze far away enemies, bad mine spawns can knock you down instantly with no way to dodge them in time, the jumping huge robots can jump at the wrong time and either dodge your cannonball or push mines towards you to knock you down…

I could go on forever but it should be easy to realize that S+ simply shouldn’t have been part of the game but since they are we have to struggle and swear and wait for the game to get kind enough to gift us with such a mighty reward.

I recommend Holly for most levels and Cactus and Starch for boss fights. Holly’s primary weapon is weak but thanks to its homing feature you don’t need to be overly precise when shooting. Her secondary weapon, the cannonball, is tiny and slow but it kills off all mobs in one hit and should be used mainly for red spiders, big robots and jellyfish, although it should also be used against weaker enemies in case you lack firepower to keep up the Chain. Use Firepower upgrades when you lack firepower and Shutdown when you are surrounded and need a health refill. Accelerate is good to quickly move around and kill small fries that are hiding far from you.

For the most part, you want to use cannonballs as soon as you spot a stronger enemy and, while you wait for the weapon to cool down, keep up the combo by killing weaker enemies. Also, whenever Green and Red jellyfishes are on the field it is a wise idea to leave at least one of them for last while you kill off all other enemies, as shooting the little floating mobs around the medusae can save your Chain in a flash if it’s about to drop.

As I have stated above, randomness will halt your runs in the majority of cases so doing this is easier said than done.

Boss fights are thankfully nowhere nearly as random as the regular levels but they are still quite hard to S+-rank. I recommend sticking to the strategies shown in the below videos and keep practicing.

The hardest levels to S+-rank are 5-4 and 5-5. 5-4 is one of the most unfair levels in the Campaign as you start with an extremely hard wave and get progressively easier waves, except for the last one where Liquorice appears. For the former waves, all I can say is to keep trying until you get lucky enough to get through them with your Chain intact. When you reach Liquorice, keep in mind that her radius for picking up batteries is larger than yours (I may be wrong but that seemed to be the case in my experience) and she can also pick up the upgrades and use them against you. Also she is fast and she can teleport to your position to execute a deadly melee attack. You win this fight if she runs out of power, which means you need to prevent her from picking up too many batteries.

Most strategies I’ve read here and elsewhere didn’t work for me so I’ll describe my own: choose Holly for this level and when dealing with Liquorice make sure a pillar is separating you from her: if you are both close to the pillar, Holly’s primary fire can go around it and hit Liquorice knocking her down after some hits. When she is knocked down, kill the surrounding enemies and pick up any battery on the field before she recovers. While you are using this strategy, you need to obviously keep up the Chain by killing the regular mobs and sometimes, no matter what you do, she will pick up a battery; unless you can safely reach it before her, I suggest letting her pick it up as you can get killed easily by her shots. Keep knocking her down with this strategy, use i-frames when in danger and don’t play risky even if this means prolonging the fight.

As for 5-5, all I can say for the first seven phases is to keep practicing and replicate what I do in the video below. The eighth phase, however, is much harder: both small and large boxes here are like mines and detonate when they touch you, there are enemies that can shot bullets and lasers and some triangular-shaped enemies that fly into you over and over when you are close to them. You have no upgrades or batteries to help you here and this phase must be completed in about one minute before you run out of power. Thankfully the game automatically maxes out your firepower during this phase. I suggest staying far from enemies and shoot them from a distance whenever possible, making sure you are always moving around. Prioritize small boxes and the triangular-shaped enemies and, when lots of boxes start spawning around the edges, get between two of them, face a direction and shoot the boxes in that direction while moving towards them (thanks to Cavalcadence for this strategy): this way you will avoid getting trapped in a circle and being knocked down. Also use the Flamethrower if the enemies are dangerously close. Chances are you will finish this phase at the last second left, although you will need many attempts and some luck to succeed.

If you are struggling on any of the 25 levels, refer to the videos below to see how I S+-rank them: