Here's a ranking of the mechanics that I based myself on to justify most of the tier list.

Grenades
Normal grenades make enemies run and stun them on explosion.
However, they aren't strong enough to kill, and since enemies run away before the explosion, normal grenades are pretty useless, unless they are equipped with Missile and Meteor Shower, which already make them quite better, though at the price of 2 plugin slots.

Heal grenades are currently not strong enough, in my opinion. They sure allow to stay up a little bit longer while fighting, but the hp gain is quite slight compared to the potential incoming damage.

Turret grenades are definitely the most interesting choice : For only one plugin slot, this can attract enemies for a decent amount of time while the player can either run away to take objectives or beat them down easier.

Speed
In this game, crouching considerably reduces the chance to get hit, but running while crouching isn't as efficient (I think?).
Speed can sure help in melee-only and boss stages, but as dash stuns nearby enemies, it's not really the thing I'd want to buff first.

Currency
Gold and nanos are used to open crates (in the crates room located near the middle of the road, at spawn). Nanos are also required for healing, but it's pretty unlikely to run out in the middle of a stage.
Very early, the only crates worth opening are legendary weapons (it's pretty easy to get all the legendary plugins from around loop 2). However, it's a lot easier to get gold rather than nanos, thanks to all the useless weapons that have to be tossed out. Currently at mid-loop 6, I have around 3.000.000 gold and ~50 nanos.
And so, nanos are definitely the currency to prioritize, and it seems impossible in any way to run out of gold.

Weapons
Weapons are the main aspect of the game, as the main source of damage. In order to progress further, anyone would have to care about getting a good legendary weapon at some point, and the rarest ones are obtainable either through boss battles or crates.
I think the Nano Hacker plugin is quite nice to have nearby, allowing to stack up more nanos for crates, and maybe get a nice gun to move on higher loops.

Rank F

Chance damaged enemies drop 300 gold

This one just had to have its own worst rank : It seems impossible for anyone to run out of gold, so what's more pointless than farming it?
The only purpose of this plugin is to speedrun to 1m coins.


Rank E

15% chance to steal hp upon damaging enemy. - Heals 3hp per occurence.

No matter if it is used with a weapon on maximum firerate, the heal is definitely not enough to compensate for enemy bullets. Sounds cool, but currently, it's not.

Grenade turns into 7m radius healing area and healing for about 20 seconds. Unstackable. - Heals 4hp a second

Definitely very weak. Throwing multiple grenades could help, but it looks ridiculous compared to the 25hp/1.5 second for nano heal.
It could come in handy for close combat enemies that don't let the player nanoheal, but at this point, a turret would do a better job.

Increase health by 50% - multiple ones only takes the player's base hp in account (100), so 3 plugins add 150hp

Another bad plugin ; more hp sure helps to tank more hits, but then, everything's worse :
-Nanoheal gives 25hp, not 25% of the health. This means when the player gets to ~10hp, it has to nanoheal 4 times, plus 2 times per HP Capacitor. Put simply, it takes ~15 seconds to fully heal with 3 capacitors equipped.
-Of course, resurrection gives back the whole 250hp, but capacitors don't affect the "knocked-down hp bar", meaning that when it's down, the player is as vulnerable as always.

Increases movement speed by 25%

This plugin is borderline useless as well : Even while crouching, running rises the chances to get hit, and speed doesn't affect enemies' accuracy.
If the player has to run because of melee attackers, dash is more than enough, as it stuns nearby enemies.
The only thing that saves this plugin from F rank is the fact that it comes quite handy against Jena.


Rank D

Grenade now chases enemies faster and explode upon contact. Unstackable.

A must-have for anyone who prefers normal grenade. As enemies always run before the explosion, being able to explode instantly is definitely a bonus.
However, I consider that normal grenades aren't especially good at the first place, as they only give a small break to the player.

Lobs 8 child grenades after explosion. Unstackable.

Only useful for normal grenades, and requires Missile to actually hit enemies (or else, they'd have already ran away before the first explosion).
That's already 2 plugin slots taken, and it doesn't buy much time...


Rank C

Scans have 50% chance to stun enemies. Unstackable.

This one is pretty good to escape from hard situations. That's a 50% chance, but it's still fairly good considering it has unlimited uses.
Pretty nice to have against Jena too, instead of speed buffs.

Immune to explosion / stumble / knocked effect.

On medium / hard, there're quite a few enemies, and they can get very fast ; I frequently get stunned, so this could sure be useful.
However, stunning also allows to exploit a powerful glitch : When the player gets KO'd while in the process of nanohealing, the progress bar will stay here for the stand-up cooldown, which means that if one gets KO'd while at 60% of healing process, the resurrection bar will start at 60% already.
Furthermore, being stunned while healing pauses the process, which means one simply has to wait to be stunned on healing, then once down, wait to be KO'd, then resurrect faster.
(This will probably be fixed lol)


Rank B

Increases grenade capacity by 10

Since grenades are quite versatile, being able to bring 10 more for only 1 plugin slot is quite interesting.
Personally, when I use them, I can hardly end a round with my grenades fully replenished from enemies drops, but grenade crates aren't too rare in between-stages areas, so this isn't that bad.

Increases range for attracting items to 20x further

As getting a good weapon is very important, Black Hole is definitely welcome in my plugin slots when I aim for farming currency, as it can save quite some time from going in all the corners for every single drop.

Chance damaged enemy drops 5 nanos

This isn't much, but still my go-to when I am facing easier stages. Nanos are definitely the main currency to aim for, so when I go in farming mode, 2 Nano Hackers and 1 Black Hole do the job.


Rank A

Grenade turns into a turret and shoots enemies. Auto-shotgun specification. Unstackable.

Being able to attract enemies at another place pays off very often. Of course, the shotgun damage is almost nothing, so this is more of a bait.
Since it can keep enemies distracted quite longer than anything else, this is definitely very useful for objective stages, challenging since enemies can endlessly respawn


Rank S

Reduces damage received by 10%

As Heist deserves its unique worst rank, I think Iron Curtain deserves the best one alone.
No matter in which situation, a player will always try to avoid getting knocked down, and turns out this is the best plugin for that.
Not only 3 plugins greatly reduces damage received, but this also means a single nanoheal virtualy restores more health at once. I started going full Iron Curtain on ~loop 5, and I always kept it since then, definitely my go-to for hard stages.

So I guess that's it for this tier list! Hope it'll have helped some people...

I also hope it will help the devs as well to have an idea of the power of the game mechanics...

Stay healthy, yall!