I know the weapon system in Nanoforce can seem hard to handle at first play BUT It's very easy!!!!
The player is carrying the grasper set composed with 4 weapons, for example, If you play with a Xbox pad, you can shot (as you want and full power) back and front with X, Homing pressing the Y button and A is the one to use special weapons (unlimited use and also full power it reduce the ship's speed a bit)
Then if you collect other items (showed here )
The config remains the same about the pad but the grapser set is replace with "cranial drills", "needledriver" "tissue distruptor" or "wave phaser".
All this news sets are using the same controls, but their weapons have different skins and behaviors...It's up to you to master them!
For example homming missiles will be replaced by two homing lasers or homing spores, frontal shot with a wider frontal weapon or a short range powerfull electric bolt..
there are other sets "exceptions", the OMNI and "scalpel" sets are composed with only one weapon but it can be fired in 4 direction Using ABXY buttons. if you want to shoot up, uses Y, down use A etc...