The default weapon, which serves its purpose well. The moderate rate of fire and decent range make it a good choice for the entirety of the game, especially during the first few boss fights.
It takes a while for the Data Bomb to travel, but it has a very small explosion effect and does a lot of damage. If you're far away and need to kill an enemy quickly, the Data Bomb is a solid choice. It's also useful in some boss fights for the same reason.
The Distortion Field creates, well... a distortion field. It looks really cool and works well at short range much like the Kilver. It's not necessarily better, but it provides a strong alternative.
The Firewall shoots downward at an angle and creates a small tower of flames. It can be very useful when you're above a tough enemy and don't want to get close to fight them. With the right angle you can just hang above them and shoot the Firewall a few times.
Hold the fire button and watch the world burn. The Flamethrower goes through walls and does a lot of damage. It can also cover a lot of ground with the appropriate range upgrades. One of the best weapons in the game.
As its title indicates, the Heat Seeker is a homing weapon that seeks out enemies. It's also fully automatic and does a lot of damage from a distance. Definitely one of the best weapons in the game.
This acts much like the Axiom Disruptor except for the fact that a few more projectiles will branch off from the main one. It's sort of like a mix between the Axiom Disruptor and Nova. Most players won't use it much, as there are plenty of better alternatives.
The Ion Beam is a simple laser beam that does decent damage. It can be hard to aim though, so it's not necessarily worth using in place of other long range weapons.
Shots from the Inertial Pulse pierce enemies, but not much else. It's one of the least useful weapons in the game.
Perhaps the best weapon in the game, at least for the first half or so. It's a circle of electricity that goes through walls and does a lot of damage. There are a few other short range weapons in the game, but Kilver is the top choice. Also consider using it for the final boss fight.
Holding the fire button targets the nearest enemy and creates a lightning chain that continues to do damage as long as you hold it. The lightning gun is effective in many boss fights, but it can be hard to pick a particular target when you face multiple enemies.
The Multi-Disruptor shoots a few projectiles in different directions. It's a short range weapon without the appropriate upgrades, meaning it's not particularly useful until the second half of the game. As with some of the other weapons, there are better options that serve the same purpose.
The Nova expands into six shots in different directions if you hit the fire button again before it touches an enemy or surface. If you want to stay back and hit an enemy in a tricky position, this works. Otherwise, just use the Nova for the switch puzzles in the beginning of the game. There are plenty of better weapons for combat.
See all those pesky enemies hanging to walls? Simply use the Orbital Discharge to take them out. It has a high rate of fire and the projectiles attach to surfaces and travel along them.
Pretend the protagonist Trace has no clue how to use a gun and you have the Quantum Variegator. It has a high rate of fire but shoots in all kinds of random directions, as if the player has no control. It looks amusing but doesn't help much in battle.
The Reflector bounces shots off of walls. The shots become quite large with enough upgrades, but it's often better to just hit an enemy head on. There aren't a ton of opportunities to bounce projectiles off of walls reliably, so it's another weapon that probably won't be used much.
The Reverse Slicer has a boomerang effect and can go through walls at a short range. There are other weapons that go through walls and do more damage, so it's not the best choice for combat.
The automatic ice shards have a very high rate of fire and are a lot of fun to use. They don't do a ton of damage, but concentrated fire on an enemy helps compensate.
Tethered Charge is a short range weapon that is easy to use and does a decent amount of damage. It doesn't top weapons like the Kilver, but it's not too far behind.
The Turbine Pulse is an in-between weapon that helps with both short and long range attacks. Holding the fire button results in a short range attack, while quickly tapping the fire button shoots a bunch of projectiles in different directions.
The Voranj doesn't do much damage, but it's one of the best weapons in the game because of its spread attack. Many boss fights are made easier with it because the player can get in a safer position and still hit the boss. Just exercise patience when using it, because it honestly takes a while to kill anything with it.