The art style is just bad in my opinion. The NOD Black Hand doesn't even look like a Black Hand Soldier, it looks like standard Nod infantry.
https://i.imgur.com/YMtrxmc.jpg
I think the Black Hand should look more like this.
https://cnc.fandom.com/wiki/Black_Hand_(Tiberium_Wars)
GDI soldier classes also look too similar to each other, all of them do except the Engineer, same with NOD. Please change the way they look.
GDI helmets also look too big and bulky compared to Nod, I think the visor should have a smaller look. It just doesn't feel like command and conquer to me, the Tiberain Sun reborn mod felt really immersive with the music and really captured the feel of Tiberian Sun, I don't think this mod will, the units look too different. I think they should have aimed to make the soldiers look more similar to the way they do in Command and Conquer 3 Kanes Wrath and Firestorm, instead it's their own art direction.
The art style just reminds me of Unreal Tournament 3 a bit, it just doesn't feel like C&C.
On second though, perhaps the art style isn't bad. I suggest the team make it look a bit more like firestorm in Tiberian Sun and I think they should change the way the GDI/Nod Helmets look to make classes look more unique because they all look similar except for the Engineer and Cyborg/Zone Trooper.
For the Unreal Engine 5 Version, I don't think it should be called Firestorm again, for Unreal 5 version I think they should make the game look more similar to Command and Conquer 3/Kanes Wrath with all the units from those games. Of course there doesn't have to be a Scrin Faction, not for the full release anyway but playing Scrin would be really cool but of course they should focus on GDI vs NOD first.