Nice update Alien-seed! Flamer thrower and Praetorian are great addons.
Couple of discussion points:
1. Praetorians:
They're praetorians right? They look great, but I think they should be bigger if possible. Also, the flame thrower should not cause them to run around like the regular xenos. Plus, they should have more HP.
2. Movement speed:
Character's walk speed is okay, but its a bit problematic when fighting synths (I assume they're synths). Could use a slight boost. Same with the running speed. Actually, I'd advise you to boost the running speed, but prevent the player from firing as they're doing so (i.e. sprinting). You may also like to boost the aliens speed as I think they might be a bit too slow right now.
3. OP Flamer:
Feels a bit OP. The flames merely touching the aliens sends them running around. Amount of damage before 'crazy-run' should be increased.
4. Levels:
Where'd the other two maps go? Didn't ever spawn in them.
5. Update numbering:
This is your project so do as you please, but for version number, I'd start with 0.10 (first release) then increase the number by 0.01 for subsequent updates. So if it were me, I'd call this 0.11, since A31 (to me at least) seems a bit random.
6. Weapon binding:
Currently, you have:
1- Shotgun
2- Pistol
3- Flamer
Spacebar-Knife
This should be (imo):
1-Knife
2-Pistol
3-Shotgun
4-[EMPTY, Pulse Rifle maybe?]
5-[EMPTY]
6-[Flame thrower]
7. Menu and Interface:
I'd suggest against dropping the player directly into the game. You have a menu already, so why not begin the game from there?
8. Content work:
This is completely up to you, but if you'd like, and when I am able to, I can try and contribute some enemy character sprites, Xenos in particular. You'd have to provide me some template of sorts though just for the sake of consistency. I have my own non-Alien related project, but the sprite work here should be much faster to do than in my own project.
Again, looking forward to the next update! Looking great, just needs more stuff.