Revisiting Half-Life 2 some more makes me think about modulation of action. Both Half-Life 1 and 2 punctuate a series of combat encounters with a long period of down time. In HL1, that is often the form of exploration and completing an objective so you can return elsewhere. In HL2 it is often just having to take note of your environment to find a disguised path or occasionally a physics puzzle. Both games also have some platforming/hazard challenges.
There are many times that I find HL2's modulation to be unsatisfying. The stop and go nature doesn't always heighten the tension like it should, but rather could easily make me disappointed that the previous combat section was too briefly paced. The game will throw soldiers with pistols at you for a long time after you are rocking the automatic and high caliber weapons, for instance, which isn't enough of a threat to break things up. Or there will be a very brief pack of enemies that don't feel like enough meat to fit in the middle of two slices of the puzzle section sandwich. There's also a period in the later chapters where you frequently stop to pull landmines ('hoppers') out of the ground, or else stop to disable an inconsiderate turret around a corner. You kind of just want to get going with the "resistance uprising" at that point!
De-emphasizing HL1's sense of exploration and mini-objectives seems to make this feel like issue when the same amount of downtime wasn't before, perhaps because it turns the game's pacing into a more conscious part of the player's experience worth paying attention to and remembering. Because it should be pointed out that HL2 is very paced at times as well. Half-Life 2 is consistently overly generous with ammo, and the resupply crates are clearly marked this time (big timesaver!). And so when you know exactly where you are going, the game can slip into more of a Doom-like "fire and forget" rapid combat & traversal experience. There's almost a silly realization that you will have plenty of ammo to use the shotgun against plain Jane normal headcrabs and zombies. Likewise, the crossbow isn't "a waste" to use as a 1-hit kill against standard combine soldiers. There's so much ammo to go around that the magnum basically stops getting use after you collect more of your arsenal.
I haven't revisited every chapter, but the courtyard setpiece where you have to protect Alyx seems like it takes the cake for hardest section. I don't think I've ever had a perfectly smooth run of that encounter. I wonder if there is some great strategy here. I tried to maintain a rear minefield of hoppers to hide behind when the final wave of enemies flood your position just as you need to leave. Preserving as much health as possible until that point was also very important, but that's all I came up with.
