There’s not many projects to get through, it’s a matter of getting through all of your research projects (especially interrogations) to unlock them all to be done.
Here’s a list of all of the projects:
Heavy weapons platform
Improved pistol 1
Improved pistol 2
Improved pistol 3
Scope upgrade
S.H.I.V suppression
S.H.I.V laser
S.H.I.V plasma
S.H.I.V repair
Improved Medkit
Stealth satellites
Alien grenades
Improved arc thrower
Ammo conservation
Drone capture
Advanced repair
Advanced flight
Advanced construction
Happy hunting!