A good, but ultimately mixed bag.
The Pros (Half-Life 2 + episodes)
This game truly has an excellent story. This cannot be understated. By the end of episode 2, you will truly care about the main characters and you will very much feel a part of the events in the game world.
This really more a testament to how Valve has truly lived up to the hype of revolutionizing storytelling in games. You really, truly feel a part of the action. Alyx FEELS like a companion rather than a character to watch in cutscenes. This is in large part due to Valve's decision to remove cutscenes, keeping dialogue in game and from first person perspective. It works.
From a technical standpoint, the game is solid. It may've been great at one point, but years have passed. That said, it is still very playable, and for an older game, you'll be astonished by just how palatable the graphics still are. I sure was, as I was dreading those "last gen graphics." Instead, the graphics looked like early this-gen, especially for the episodes.
The gravity gun is also, to this day, a great mechanic. While many have tried physics related gameplay, the gravity gun still plays the part to perfection. The physics based elements can be frustrating and can divorce one from the game world, but Valve gets an A for effort. More impressive is the freedom Valve gives you in the sheer amount of stuff in the game world that can be picked up and tossed.
The Cons
Valve tried far too hard, in some regard, to make this title a revolutionary one. In some respects, i don't think the game would've been as much of a landmark had they not pushed themselves to make something totally different in all ways, but this comes at the cost of failures in some areas.
For starters, first person platforming here is rudimentary, awkward, imprecise, and generally crap. Often times, where to jump is ambiguous (sliding down a rocky cliff), something that is made all the worse by being unable to see your own feet, making you unsure of what exactly Gordon will be able to stand on/fit onto.
This leads to the other big beef I have with the game. Not being able to see your hands or feet is not at all immersive...it's just weird. Seeing wheels magically spin by themselves or cars drive themselves is just utterly off.
Also, there are driving portions that are a tad too long in Half-Life 2 (the episodes are fine). This leads to much of that great storytelling falling to the wayside with the game becoming a chore. You spend such long periods wandering/driving by yourself and facing obscure "what do i do now" puzzle situations that the story becomes inconsquential. Thankfully, Valve seem to become better storytellers as the game progresses. Once past the "Sandtraps" stage, these dry periods pretty much stop and the story once more becomes central. The episodes do not have this problem at all.
Team Fortress 2 (pros)
The game has a GREAT look/atmosphere and the cartoony graphics are excellent. The way the various character classes are differentiated and each given their own, well, character, is also truly inspired. The ominous female voice that makes the announcements is also fantastic.
On a gameplay level...as a class-oriented shooter, it works. However, this requires a substantial amount of teamwork for it to play well.
the Cons
I find the maps to be totally boring, limited, and uninspired. I've also frequently had problems with lag (keep in mind i play CoD 4 and Resistance, among other games, with no lag whatsoever). Several times, lag has rendered the game unplayable.
Also, while i doubt this would be as much of a problem on the PC version...well, remember what I said about how integral teamwork is to the game actually playing well? Teamwork on Xbox Live is often impossible, usually due to many players not having or not using voice chat, turning the game into a chaotic mess that is often impossible to perform well in.
In the end, while TF2 certainly has its fanbase, I am not among them.
Portal (The Pros)
Truly the shining light of the Orange Box and a game that seemed to rise to become the face and spokesperson of Valve in all its quirkiness. Aperture science and "the cake is a lie" superceding Gordon Freeman? Yup
The game is unique, arthouse, experimental, and utterly fresh and new. It takes a revolutionary gameplay mechanic, fine tunes it to perfection, and then exploits it in every way and direction possible, taxing the gamer in a manner that is challenging, addictive, but never unfair or overly frustrating. In other words, it's not made by Itagaki. (couldn't help myself)
While there isn't much game here due to its length and due to the game really just being an extended muck-about with an exceptional and new mechanic, Portal seems self-aware of this, never over-reaching and never aiming to be more than it is. For that, it's length and limited nature are forgiven. It never goes for too much, and while short, the length ensures that the game never gets old and that it never feels recycled or repeated. It keeps introducing new ideas to the mechanic, building upon itself until reaching its necessary end.
The Cons
Not many, honestly. Some might sight the short length, but i feel that the length is perfect for it. That said, the length also ensures that it doesn't feel like a full, 59.99 game. That said, it isn't one and it neither tries nor purports to be.
Portal set out to do something and it did everything it set out to do.
The Conclusion: An epic watershed of a game that must be played due to what it brings to storytelling and fps that goes from being tedious work to something truly engaging. A mediocre team based game that is for some, but not all. A brilliant puzzle side-game. That's what you get in the Orange Box. Is it worth picking up? Despite all I've said, you bet it is. If anything, you can't beat this value.