The game so far is great, what I would like to see and I'm sure many others, is a neat "ammo check" animation, instead of just patting down your pockets I think it would be cool to see the character check his chamber or even unclip the mag to look at the bullets really quickly then slam it back in.
The last insurgency game felt kind of bland with its progression. This one I'm hoping for some difference. Although I'm sure you are already planning to add something that makes levelling up worth it, Instead of just buying clothing from currency you get from levelling up, I think you should make it more rewarding. When we level up I think we should unlock camos for out gun, unique ones that can only be obtained by levelling to that specific level. For instance, level 100 = Shiny Gold camo. Or something, you get the picture. Or you could go the route of unlocking camos for certain guns when getting a certain amount of kills with the said gun.
Additionally, I think it would be neat to change up the gun system, instead of just having access to EVERY gun, I think you should make them level-dependant, so you unlock more guns as you level up. For the attachments, I think we should have to get kills to unlock more attachments for the certain gun.
With those two new systems, I think it would drastically change the game in a good way, it adds variety that the first didn't have and it makes us WANT to continue playing, makes us want to get kills and win the game because we get rewarded for it.
That's all I have for my suggestion, I do hope this gets some support and I hope the devs notice this. This would be a neat addition to the game considering the last one didn't have this sort of variety.