We got our first glimpse at Half-Life: Alyx today, Valve's full-length VR-only Half-Life game due in March. We've already learned a lot about Half-Life: Alyx, most notably that the game takes place between the events of Half-Life and Half-Life 2, while Gordon Freeman is still in stasis and a younger Alyx Vance is trying to fight off the occupation of Earth by the alien Combine.

But what does the reveal trailer tell us about this earlier version of City 17? Here are the most interesting things to be gleaned from the footage.

Dr. Breen isn't in charge of City 17 yet

Markedly absent from the reveal trailer is the iconic presence of Dr. Breen's face on a giant video screen, which introduced us to City 17 in Half-Life 2. The actor who played Wallace Breen, Robert Culp, died back in 2010, but while Eli Vance (voiced by the late Robert Guillaume) is being played by a new actor (James Moses Black) there was no mention of a replacement actor for Breen when designer Greg Coomer gave us the lowdown on the cast.

It looks like Breen might not yet have arrived at City 17, or at the very least hasn't been appointed administrator yet. Note: I initially thought the deep and menacing voice saying "You will not save him" and "Alyx Vance alone cannot prevent his fate" might be a new bad guy, though it's been pointed out it's most likely a Vortigaunt.

Dog? Here, boy!

So, where the hell is Dog? Alyx says in Half-Life 2 that her father Eli built Dog "to protect me when I was a kid." The Alyx of this game is clearly an adult, so Dog must have already been built. But he doesn't show up in the trailer.

I wouldn't worry. The relationship between Alyx and Dog is too strong to not bring into this experience, especially in a VR game. As in Half-Life 2, it makes sense for Dog to be missing from action for most of the game. If you had a giant protective robot capable of knocking over armored Combine personnel carriers and ripping the brains out of Striders, that wouldn't give you very much to do. It's likely a decision on Valve's part to hold a big moment back as a surprise.

A helpful New Zealander fills in for Dr. Kleiner 

Alyx is assisted by a guy with an accent that makes the words "Combine chatter" sound like "Combine cheddar," but who is this helpful New Zealander? He comically throws Alyx a loaded gun and speaks to her constantly throughout the trailer, talking about acquiring a weapon and providing commentary on the plot. I'm getting the strong feeling he's going to be filling in for Dr. Kleiner, our resident bumbling scientist slash comic relief, who doesn't make an appearance in the trailer.

All we might know about this newcomer is his name, which could be Russel—a screenshot given to us by Valve is titled 'Russel's Lab', so this could be his sanctuary for tinkering and giving you instructions over the radio.

There are plenty of familiar monsters, plus—is that a sacktick? 

Headcrabs were confirmed immediately in the trailer, and we also see rampaging antlions, neck-snaring barnacles, and a variety of zombies, including one who seems to have some sort of electrical attack. But we also see a small, glowing, skittering creature with a long tail very briefly in the beginning of the trailer that doesn't look quite like any of the aliens we've seen before in Half-Life.

It's possible it could be a sacktick, a critter that was planned but ultimately cut from Half-Life 2. They were intended to be delivered by the Combine in pods the way headcrabs were, to bombard and weaken human forces in advance of an assault. The Half-Life 2 beta sound files also contained a reference to sackticks, which were going to be launched at the Borealis—the ship from Episode 3 we never got to visit.

I'm not positive, but sackticks could finally have made it into the game. Maybe they were an early invasion tactic that the Combine abandoned before the events of Half-Life 2, and that's why Gordon never met one. In any case, sacktick has gotta be an all-time best-worst enemy name. 

Half-Life: Alyx has Pipe Mania 

Remember the first time you hacked a robot or vending machine in BioShock? And you were like, oh, this is a Pipe Mania minigame? (Or Pipe Dream, or just Pipes). Well, the instance of hacking we see in the trailer is Pipe Mania. Yet again. Alyx is trying to hack some sort of power transformer, and you can see the sections of bent 'pipes' she needs to align so the power can flow freely to complete a circuit.

It's not the only puzzle—there's a very brief glimpse of another one I tacked onto the gif above that looks like she's trying to align some nodes in some sort of 3D spatial puzzle. Hopefully it doesn't have anything to do with a plumbing game from 1989.

You heal through your hand, and there's a slug involved 

I've watched this clip about 20 times and I think I'm parsing what's going on. To heal you'll need to stick your hand in the health charger—it makes the same wonderful sound it's made since the original Half-Life. ALyx's gravity gloves show her health status: during the clip it goes from zero hearts to one heart. Note that healing keeps you standing in one place, but you may still need to defend yourself. Get ready for some multitasking.

And it appears the health charger is feeding from some kind of alien slug or grub that's been crammed in the tube on the right. As Alyx heals, the slug is slowly absorbed by the machine. Is that what health and HEV chargers have been running off of all this time in Half-Life universe? Weird alien slug juice? Guh-ross.

There are some fun new weapons available 

You're gonna have to scrounge for ammo, though. Rather than leave bullets lying around in plain sight, we see Alyx having to clear off a shelf of crap to find a shell to load into one of the new guns, which appears to be a futuristic sawed-off shotgun. We also get the briefest of glimpses of Alyx firing an orange burst from another new gun—a gauss pistol, maybe? And the Combine seem to be armed with some new-looking SMGs that I assume we'll also get our virtual hands on.

Plus, Alyx's gravity gloves come in handy for pick-pocketing a Combine soldier from a distance, and hurling a crate full of foam popcorn at another. We'll have lots of new toys to play with.

He's back 

I knew it, you knew it, everyone knew it. But it's good to really know it.