It's the first weapon we have in game, it's mostly weak and should only be used on Scorpions and Anubis Warriors. Using it on Mummies or Guardians of Bast isn't probably the best idea and will probably result in death. We start with this weapon, it's not collected anywhere.
Second weapon in the game, not too much. But we shouldn't be greedy at the very start of the game. Right? We can kill most enemies with it, but it's still dangerous to use it on monsters higher in rank than Birds of Prey or Wasps. We gather it at Tomb of Ramses, at the very beginning of the map there are no enemies, until we collect it.
Probably the best of the first weapons in the game, M-60 is a fully-automatic machinegun which is better to use if you will run out of Mines or Cobras etc. There's no danger using it against anyone, maybe just Kilmaatikans or bosses like Selkis or Kilmaat Queen. We get that one two maps later, in Karnak Sanctuary.
Amun Bomb Edit
The most useful weapon in game, with high explosion radius and ability to use it under water. All things that will be in explosion range will explode or will be set on fire and die, ability to use it under water is pretty useful. Because it will be easier to take out Piranhas, than using a machete, but there are better weapons for under water. This one is gathered in the further (but not much) part of the game, in Amun Mines.
Flame Thrower Edit
A good weapon, it is probably the best one. It sets all enemies in flame radius on fire and the fired flames will fly until hitting someone or something. Also it's draining weapon power very fast, when having full power you will have empty weapon power after like 6 seconds of constant shooting. We gather this one in Cavern of Peril.
Cobra Staff Edit
The best weapon of the ones, that can be used under water. And the best of those used normally too, it shoots projectiles similar to those ones fired by Mummies. The only difference is, that they are green. It has something like 15 shots before running out of weapon power. We get it in place after the one we get M-60, the Heket Marsh.
The Ring of Ra Edit
One of good weapons, Ring of Ra is a ring
(THX Captain Obvious) and shoots small bomb like things, which bounce when hitting surface. That's all about it, oh and we get it in Magma Fields.
Additional Information Edit
In the PC version of PowerSlave, the Ring of Ra is not included. Instead of it, there's a weapon called "Mummy Staff". It shoots projectiles identical to these ones fired by Mummies, but they're white. While still homing and with pretty huge damage, this weapon is pretty overpowered.