Microsoft has announced exciting plans to expand the Xbox 360 classics library, with the technology giant confirming that both 'Halo 3' and 'Halo 4' have been added to a list that already features more than 400 titles.
Despite this, a recent blog post from 343 Industries revealed the firm were being extra careful with the popular 'Halo' titles before they were made backwards compatible.
And video game enthusiasts have been warned that the launch of other 'Halo' titles as being backwards compatible may still be some way off.
The blog post read: "We know everyone is very eager to get their hands on the Xbox One back-compat release of 'Halo: CE Anniversary,' 'Halo 3', 'Halo 3 ODST', and 'Halo 4'.
"We are eager to get them into your hands! The Xbox back-compat team is hard at work on final polish and we continue to work closely with them to help test and evaluate all four games for launch.
"We're taking extra time to ensure the experience lives up to fan expectations but I hear we're making great progress and release should be getting closer.
"As soon as we have a final date we'll be sure to let you know. (sic)"