Definitely the best thing to happen to the HALO series on PC, getting all the games that matter upto HALO 4 on the platform! I'm not always the biggest FPS guy, preferring RPGs over FPS games anyday, as well as Minecraft for the fun of creation. That being said, HALO has a fantastic sci-fi setting, and is so beyond fun to play with friends that it has to be experienced. You also have access to 6 games in this collection:
HALO: Combat Evolved
HALO 2: Anniversary
HALO 3
HALO 3: ODST
HALO Reach
HALO 4

The only thing this collection could use, is the ability to have the game split-screen EVEN on PC, down to especially the fun of co-op campaigns back on PC. After all, you're not getting co-op and split-screen even on the Xbox One here, so your best bet is if Microsoft and 343 actually fixes the PC release to give us such a huge mainstay for HALO.

I can't help myself not to address the issue of DRM in games that never had it to begin with, or in general. You see, if you played the original games in their original form, you'll know that you did not need an internet connection to enjoy these games. Playing online was an OPTION and you weren't required to sign-in to play the campaign, local split-screen, or LAN, knowing this I checked that you could play offline without using an account. Frankly I was lied to and instead to play offline you must sign in first -_-. I know not many people care enough about consumer rights these days, and instead of acknowledging the issue they'd rather tell you "just sign in bro". Another Steam user brought up this very point and got ridiculed for it, anyhow I just wanted to give my opinion and hopefully bring this topic back from the dead since Ubisoft is on everyone's radar.

I don't usually give reviews, but I'm so irritate I do feel I should warn people of what they can expect. Not a review of the game itself, but a complaint about MS very aggressive dark patterns approach of requiring a microsoft account to access the game once you've bought it on steam..

Once starting the game the UI locks you into setting up an account and providing a worrying amount of personal details - the only way you can exit the interface is to bring up task manager and kill the process.

The details it currently asks for are...

Sign up to MS terms and conditions (30 pages of dubious practices, passing of personal data to the US to avoid local laws? Expect to find the most concerning stuff around 80% of the way through. Links through to pages that are only vaguely relate to what you need to know.)
Full Name
Email address (to be verified via email, then through to web - cookies etc added then)
Date of Birth (like seriously? Over 18 not enough?)
Password (moderately secure)
Then you need to provide a username to appear on the xbox live network (which you will HAVE to be logged into every time you play the game - even if you only ever want to play single player).
Permission to link to your steam account - yeah no thank you! (again hard to see how to avoid).

Okay, everything finally entered, verified, linked. Then you're finally set up and can play.... for about 2-4 hours. During play, a login box will pop up stopping you in your tracks. "We've noticed some suspicious activity on your account and have locked it. We require you to provide your mobile number to be sent a code to unlock again". Yeah... I call bs on that. This is just a slow creep of gaining as much personal information as they can - possibly so they can make connections to other MS owned companies and services for extra ad targeting. Next time I go onto LinkedIn - "How did you enjoy Halo?". Wholly unnecessary to play a game. And if I provided this information where will the continual drip feed of personal information end? What, you need bank details next time? I've already paid for the game ffs!!!

Next to no help information on this issue online - maybe MS have been taking it down?

Totally unacceptable behaviour in this day and age, when we're becoming more aware of the dangers of not keeping our personal information private. Can't recommend because of this - which is a shame. Games themselves are pretty enjoyable!