One of the biggest challenges I came up against in Heaven’s Vault was figuring out which little squiggle meant “and.” It’s an important word. As I sat around a dusty moon, trying to piece together fragments of a long-forgotten alien language, that one little word was what I needed to link things together. Once I finally figured out, it was a “Eureka!” moment. So much of what I had been struggling with suddenly fell into place.

There are plenty of games that purport to be about archaeology and exploring ancient cultures. Most times, though, it’s little more than a backdrop for an action game, whether it’s Nathan Drake stealing treasure in Uncharted or Lara Croft raiding tombs. Heaven’s Vault is different. It stars an archaeologist who actually does archaeology. You spend most of your time translating ancient symbols while exploring the ruins of a lost civilization in search of artifacts, and it’s like nothing I’ve played before.

Heaven’s Vault takes place in a curious universe that feels both ancient and futuristic at the same time. You play as a young archaeologist named Aliya who is joined by a mouthy-but-helpful robot named Six, and you start the game by searching for a lost scholar. The world, known as the Nebula, consists of a series of moons that are all connected by a strange river of wind you sail through on a wooden ship that’s jam-packed with old books.

In the beginning, all you really have to go on is an old brooch, which was given to you by a longtime friend and head of the galaxy’s seemingly most notable university. It’s not a lot of information; there are a few hieroglyphic marks in a language no one even understands anymore. This act of translation is your main way of interacting with the game. You start out by just guessing a few symbols, but as you encounter new texts — whether it’s an inscription on an old religious statue or scattered pages from an ancient book — your vocabulary steadily grows.

This all unfolds in a way that feels incredibly natural. Every time you encounter a new group of symbols, you’re presented with a screen that offers a few options for what each word might mean. Early on, you’re straight-up guessing. But eventually, you’ll start to see patterns and discern meaning from context. For instance, you might realize that a symbol means “fire” because it’s inscribed above a hearth, or you may notice that the symbols for “star” and “light” look similar. When you correctly use a word a few times, the game will confirm that you have the translation right. Similarly, if your guess turns out to be wrong, eventually, Aliya will realize something’s off.

It’s a bit like playing sudoku; the more words you uncover, the more the big picture comes into focus. You start out translating simple, short statements, but eventually, you’ll have to tackle much longer texts. It’s a very satisfying process. The amazing thing, though, is that in Heaven’s Vault, you’re not just uncovering a language, but you’re also learning about long-gone cultures. As you learn words, you also learn about where they came from and what they mean to people, whether it’s an object of religious significance or a mysterious observatory. It feels like a grand chase. Each word or object you discover can lead you in a completely new direction, sometimes even opening up brand-new places to explore.

This all ties into the modern-day story of Aliya, which plays out sort of like a Choose Your Own Adventure-style narrative crossed with an open-world game. (Heaven’s Vault developer Inkle previously made 80 Days, which had a similar vibe.) Most of this plays out through dialogue. Heaven’s Vault is an incredibly chatty game, sort of like a more serious Oxenfree, and conversations happen constantly while you’re walking through a sandstorm, trapped in an old ruin, or flying across the galaxy. You’ll spend as much time arguing with Six as you will translating hieroglyphs.

The game is also incredibly open. You can travel virtually wherever you want, following whatever trail of clues interests you the most. This really adds to the sense of discovery, but it can also make Heaven’s Vault feel overwhelming at times, particularly toward the end when you’ve discovered a lot of places to visit. This feeling is only exacerbated by the flying segments, which you’re forced to participate in whenever you move to a new moon. They look gorgeous — like you’re speeding through a Roger Dean painting — but flying is slow and tedious, and it doesn’t add much to the experience.

That slow pace is also key to Heaven’s Vault. It’s not a game filled with thrilling set-pieces. (Let’s be honest, we have enough of those.) Instead, its thrills are much more subtle and often much more satisfying. Who knew discovering a three-letter word could be so exciting?

Heaven’s Vault is available now on the PS4 and PC.