It's Halo. An iconic game series that has it's influence across all modern shooters today. For the price of the entire collection you get 6 Halo games. Halo CE, Halo 2 and Halo 3 are considered masterpieces in the gaming world, a must play. Halo Reach and Halo 3 ODST are very good games in their own right. While Halo 4 has flaws, the game is still pretty decent. All in all, none of the games in the collection are really "bad" per se.
The single-player campaigns are very worth it, that experience has been relatively untainted by the porting to PC. In many ways, it has even improved the graphical quality of the original games significantly. The full campaign experience of all the Halo games here are very worth it and is something you should definitely be interested in playing. Do a blind playthrough of all the games. I personally recommend playing the games in the canon order which is:
Halo Reach, Halo CEA, Halo 2 until the end of the mission Metropolis, Halo 3 ODST, The rest of Halo 2, Halo 3 and Halo 4
(No problem with playing ODST after Halo 2 though or even Halo 3 if it feels a bit messy and out-of-place)
You can also play in release order though if you wish.
However, there are definitely some flaws in the multiplayer right now. At least when it comes to online matchmaking. Controller players are given aim assist so incredibly powerful that it makes using keyboard+mouse a direct disadvantage. A lot of matches with ranged weapons in general and very dumbed down and dull on the pc version. Ranged weapons in close-quarters maps isn't an issue since those matches rely entirely on who can best use the weapons to get kills. However in large maps, such as those in vehicles, ranged weapons are far more powerful than you would think. It's bad enough that people pretty much avoid using vehicles so they don't get spammed from across the map and die before they can use them. It's not fun to play a match where sitting back in spawn with a ranged weapon and shooting across the map is more effective than using vehicles or power weapons.
EDIT 26/07/2020: After playing more matchmaking, I really recommend that new players play auto slayer instead of precision slayer. Precision slayer has the flaws I mentioned above and results in boring matches but auto slayer allows you to use halo's sandbox elements for more fun and varied matches.
Another major issue is with the servers themselves. Because of a low playerbase, EU players suffer immensely. I imagine the same will be true for all regions except NA. You're usually forced onto US servers where you're at a disadvantage. There are many other bugs with the multiplayer such as Halo 3's hitreg being godawful but right now the online multiplayer has some serious bugs that need to be fixed. 343 is continuing to work on the game and hopefully they eventually fix some of the bugs that are present. Halo's multiplayer is good but there are some major flaws that prevent it from reaching it's former glory.
That being said, hosting custom game lobbies with custom modes and maps still provides limitless fun and entertainment for you and your friends. It's a good way to balance out the current problems with online matchmaking right now. Halo's custom games have the potential to be some of the most fun experiences you can have in gaming so I recommend you try them out at some point.
Other features exist like Firefight which is a PvE mode where you have to survive against hordes of enemies. There's also Forge which lets you build your own custom maps that you can share and play in custom games. There is also theater mode which lets you take screenshots and record clips of gameplay. All these features play a part in what makes Halo so great.
As of this review however, only Halo Reach, Halo CEA and Halo 2 have released on PC. The rest have not released yet but are in the works. Buying the entire bundle buys all 6 games, it's just that not all of them have released yet. When they release, you will get them. Some of the features I mentioned in the review such as Forge and Theater have not fully released yet either but are coming.
My final verdict is that the entire bundle is worth it. If there is a sale however, it's a must-buy. When all the games finally release it may very likely become a must-buy. It absolutely will become a must-buy if they manage to fix all the bugs.
