I could suggest making the plasma launcher use mana instead of grenades since that's what was used in Halo Reach. Speaking of which the plasma launcher's tracking projectiles are strong enough to track targets far away that I'm not aiming at and they'll go through blocks just to get to them LOL. Also like all the grenades, even the UNSC grenade launcher, they have the consistent volume issue where you can still hear the explosion no matter the distance. Strangely the concussion projectiles do not have this issue.

@Kid Justice Gaming
I said this before but I will say here, but a lot of the gun sprites are honestly far too detailed and don't fit the Terraria pixel sprite style. Just something to consider, please see several sprites as reference to help. I'm glad you are already working on making the sprites smaller so I wish you the best with your improvements and hard work. https://steamhost.cn/steamcommunity_com/profiles/76561199122399638/myworkshopfiles/?appid=105600
https://steamhost.cn/steamcommunity_com/id/Stingrays110/myworkshopfiles/?appid=105600
https://www.reddit.com/r/halo/comments/l5gzrr/terrariastyled_halo_version_2_more_stuff_edition/

I can suggest brute spike grenades and some of the Halo infinite weapons to add more variety or even tweak them as progression for other mods.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2476853566&searchtext=brutal
Here. I suggest taking a look at the laser machinegun projectiles in this texture pack. This might help with the textures for the light rifle. Because it shows that you just have to have one single projectile sprite with two glowing points and it moves much more smoothly.