The Deep Down mod for Half-Life 2 is a fairly extensive walkthrough mod that covers the events around White Forest. Basically, it's based on Half-Life 2: Episode Two. In this article, I'll try to assess how well the authors have accomplished this.
The mod was highly rated back in the day, so I decided to give it a try. But I only got around to it now.
The mod begins at a rebel base during a Combine attack, and Freeman and Alyx are sent to attack (it's unclear where and why, but we came here to play a shooter, right?). The machine has a new feature: it can disable Combine force fields by right-clicking. Unfortunately, in practice, this only works once per game. The mod doesn't look very good.
The balance has been slightly tweaked. Turret damage seems to have been increased. They're nuclear-powered. The levels aren't exactly monotonous: there are forests, mines, and bunkers. But then again, it's all still within the confines of Episode Two. Furthermore, questions arise regarding the logic of what is depicted. For example, what is a marine cargo crane with an electromagnet doing in the mountains (I assume, judging by some snow-covered trees, these are mountains) without any nearby ships, railways, etc.? More about the bugs: the elevator on the aforementioned crane also works very "interestingly": the button inside the elevator only sends it down.
The button below can send the elevator both up and down, depending on its location. Therefore, to go up, you need to press the button on the support, but to do this, you need to exit the cabin, and the elevator will go up without you. Only after a few minutes of "acrobatics" did I notice that the elevator goes up on its own if you wait a while. Why they couldn't make the button inside the elevator work the same way as the button on the outside is a mystery. You probably remember that in the original Half-Life 2 there was a similar scene where you used a crane to lift a car and move it to a place it couldn't reach on its own, and then opened a bridge for yourself? Well, this is a complete parody of that very same scene. It's amazing how much worse they could have done, but they really did their best.
As soon as you climb into the crane's cabin, two soldiers appear, firing at you. Don't try to kill them with crates: a new one will simply replace the one killed, so there are always two of them. And when you exit the crane, both enemies disappear.
In Half-Life 2, there were a lot of enemies, and crushing them with crates was fun: the thrill of killing as many as possible with the crane so you have to eliminate fewer once you're down. But here, there are always two of them, no matter what, they just get in the way. These guys just didn't get the point.
At one point, we'll be asked to tediously figure out how to open gates in the tunnels to drive a car further. By the way, I didn't understand how to get past the last room. But opening the gate is not necessary here. And you don't even need to take the car with you. There are no force fields further on, which the car is needed to open. You can simply proceed forward on foot. Alyx will teleport to you when the level loads. This is how the gameplay is variably played: you can choose to have a car, or you can choose not to.
One of the mod's strengths is that there are virtually no "Where do I even go next?" moments, and the levels are fairly logical.