During Composer, you can find some Covenant trying to enter the station through the airlocks. To proceed, you can either give them enough time to figure out how to open the hatches and fight them, or send them hurtling off into space.
The Roses vs Violets achievement requires finding one Red vs. Blue easter egg. One is found in each episode.
In Episode 1, Caboose fills in for a UNSC radioman.
In Episode 2, audio logs from a doomed science expedition gets replaced by Caboose, Church, Simmons, and Grif.
In Episode 3, Grif and Simmons pilot the Pelicans that deliver Mantises to the player(s), exchanging their characteristic dry commentary on military combat.
In Episode 4, Vic is back and apparently got Palmer's number after some karaoke.
In Episode 5, Grif and Sarge deliver you some sports equipment. This one's notable because it actually changes the way the game is played. Have fun running up close to Hunters and Wraiths with Gravity Hammers.
In Episode 6, Sarge and Grif prank call the Infinity.
Grif: Baba booey! Baba boeey!
In Episode 7, Simmons is trying to fix the Infinity's engines.
Simmons:Oh great! More people with guns. I'm sure THAT will fix the engine.
In Episode 8, Caboose is called to deliver suppllies.
Caboose:Six crates of elbow grease and headlight fluid inbound now!
In Episode 9, Church argues with an Elite.
In Episode 10, Agent Georgia finds jetpacks - it won't end well.
In the intro video for Episode Two, a Forerunner artifact shuts down Infinity's engines and sends it falling towards Requiem. Palmer solves the problem with a power-armor assisted kick to the artifact, reactivating the engines. She later comments that further attempts at "physical persuasion" haven't had any additional effect.
Roland: There you are, Crimson, get up there. I command it! Haha! Okay, now I'm bored again, bye.
In Episode 5, With Palmer gone Miller is left to lead you through the missions and Roland decides to take the oppurtunity and mock him and you whenever he can.
Chief's Character Of The Year VGA Acceptance Speech. Cortana shows up and hypes up the speech, saying he's been practising "All week." Pan over to Chief, who shuffles around nervously with the statue, and then...
The nomination video was funny as well. Cortana mentions how great an honor it is, while the Chief, leaning back in a chair, plays it down, suggesting all he needs is the respect of his fellow soldiers. Cortana then mentions Samuel L. Jackson is hosting, which causes him to fall out of his chair and say he needs to find a tux.
In Episode 8, after Majestic Team kills an Elite they start playing around with with its gear. DeMarco gets his energy sword. Thorne plays with his active camo. Madsen gets... a map of Requiem. He doesn't sound too pleased about it.