I thought I’d just get this out there to see if it was intentional or not (I don’t think it is). Both me and my friend killed people by charging up the Plasma Pistol and meleeing them, and we both got the “Special Delivery” achievement (Killing someone with a melee attack while landing from a man cannon)
Has anyone else encountered this glitch?
no…
but im about to
I did but then my achievement got taken away…I’ve never had that happen
I meleed someone and they killed themself and me with a rocket and I got it. That’s not the only glitch though. I have 56 of 57 achievements in Halo 4 and it says I only have 49 of 57 and still at 1000 Gamerscore. I hope this gets fixed.
Lol same here, but shhh don’t tell free gamer score 
I unlocked ODST from getting a hail mary…