Naughty Dog finally released Uncharted 4: A Thief’s End, the long-awaited sequel to one of the PlayStation’s most popular and critically-acclaimed franchises, this week. Much like Nathan Drake’s penchant for locating relics from the past, there are quite a few interesting Uncharted facts to be dug up. Naughty Dog is a company that likes to go the extra mile with their games, and it shows with the sheer variety of cool details that can be unearthed with this series.

Here are a few bits of Uncharted trivia that you may not have been aware of.

12. Ottsel Wetsuit

Naughty Dog loves to stuff their games with Easter eggs, especially ones that reference their own games. While some are easier to spot than others, there’s a pretty good chance you missed a reference to one of Naughty Dog’s other franchises near the beginning of Uncharted: Drake’s Fortune. In the first chapter of that game, Drake is outfitted in a wetsuit. If you look closely, you can see that the wetsuit is branded as “Ottsel,” the made-up animal species that the character Daxter is in the Jak & Daxter series. There are a few other Jak & Daxter callbacks throughout the Uncharted series, including the Strange Relic treasure, which is actually a Precursor Orb (but you probably already knew that).

11. Victor Sullivan’s Plane

Another callback to an old Naughty Dog game, the name of Victor Sullivan’s private Grumman G-21 Goose seaplane is “The Hog Wild.” Savvy fans likely figured out that this is the same name as a level from the first Crash Bandicoot.

10. “Dude Raider”

In addition to Indiana Jones, the series that Uncharted most often gets compared to is Tomb Raider, as both franchises have many similarities, including attractive protagonists who hunt for treasure in exotic locations. Prior to the release of Uncharted: Drake’s Fortune in 2007, the game was labelled by some as “Dude Raider” due to it looking like little more than a gender-swapped version of Tomb Raider. Both series have since evolved to the point where they are quite a bit different from one another, but the Dude Raider nickname remains a humorous reminder of a time when Uncharted had to prove that it was more than just a Lara Croft imitator.

9. Nathan Drake’s Johnny Knoxville Connection.

Uncharted protagonist Nathan Drake is often described as an “everyman” adventurer thanks to his penchant for exploring tombs while wearing jeans and a half-tucked shirt, but it may surprise you to learn that his original likeness was modeled, at least in part, after actor/stuntman Johnny Knoxville. We don’t really see the resemblance (it’s even more difficult now that Drake’s appearance has changed so much with each subsequent game) but this must come as a bit of surprise to fans who swear that Nate is really Nathan Fillion.

8. Uncharted 4 Controversy

Anyone who has played Uncharted 4 can attest to the strength of actress Laura Bailey’s performance as antagonist Nadine Ross, but Naughty Dog still came under fire for casting Bailey in the role. The reason? Bailey is a white actress portraying a black character. Game Director Neil Druckmann responded to allegations of racism, arguing that the choice to have Nadine be a black character came about organically during the concept stage and that Bailey had already been cast in the role prior to the final character design approval.  He also revealed that there is a white character in the game portrayed by a black actor. Whether or not Naughty Dog was in the right with their decision, it’s a fascinating issue that will probably only become more pronounced as games increasingly rely on the talents of voice actors.

7. Charlie Cutter

One of the best surprises in Uncharted 3: Drake’s Deception was the introduction of Charlie Cutter, a Jason Statham lookalike who could crack wise just as well as Nathan Drake. If you thought that Charlie’s exit from the game about midway through felt a bit abrupt, there’s a good reason for that. Actor Graham McTavish, who gave voice to the character, had other commitments while the game was being made and had to have his character written out early. McTavish was actually supposed to reprise his role for Uncharted 4, but his part ended up being cut.

6. Emily Rose’s Accidental Role

Emily Rose got her big break by playing Elena Fisher throughout the Uncharted series, but she never actually intentionally auditioned for the part! Rose accompanied a friend to the audition and got a callback because Game Director Amy Hennig noticed that she had great chemistry with Nolan North, the actor who plays Nathan Drake.

5. Nathan Drake’s Real Pain

Nathan Drake should probably be dead about a thousand times over by this point, with the amount of broken bones and gun shot wounds he’s sustained over the course of the series. Apparently, Nolan North wanted to experience a bit of this pain himself; how else to explain why he did motion capture for Drake’s Deception while suffering from broken ribs? One thing’s for sure though: that extra pain definitely helped make the anguish on Drake’s face look even more realistic!

4. Not Gob’s Boat

Naughty Dog doesn’t just reference their own games; they also like to hide Easter eggs to popular TV shows. In Uncharted 3’s 12th chapter, it can be seen that the pirate Ramses’ ship is called “The Seaward.” Observant fans might recognize this as a reference to Arrested Development, as the character Gob (Will Arnett) has a boat with the same name (although in Gob’s case, it’s actually called the “C-Word”),

3. More On-Set Injuries

Nolan North sure seems willing to go through all kinds of physical trauma to do his job. In an early chapter of Uncharted 3, you may recall that a young Nathan Drake is almost shot by a man who tells him to “close his eyes” before Sully steps into save the boy. As it turns out, this mystery man is voiced by Nolan North, who had to subsequently play a corpse for the rest of the scene after Sully “shot” him. This actually resulted in an accident where the heavy plastic stand-in gun that Sully takes from Nathan hit North in the head after Sully throws it behind him, almost knocking him out in the process. Ouch.

2. Drake’s Age

Although Nathan Drake’s age can be ball parked as mid-to-late 30s based on his appearance, he does have a canonically determined age in each game. When we first meet him in Drake’s Fortune, he’s 31 years old. Uncharted 2 and 3 are each separated by a two year time jump, which puts Nate’s age at 33 and 35 in those games, respectively. In Uncharted 4, Nate is 38, as the game is set three years after the events of Uncharted 3.

1. Uncharted 2’s Train Sequence Almost Broke The Entire Game … In a Manner of Speaking

Many fans still consider the train sequence in Uncharted 2: Among Thieves to be the best in the series (in fact, we ranked it number 1 on our list of the franchise’s best moments). It’s a good thing that that sequence is held in such high esteem too because it almost derailed (pun intended) the entire game. As explained in a lengthy 2010 post from The Escapist, Naughty Dog’s Richard Lemarchand considers the process of getting the sequence working correctly to be the company’s lowest point, as it required months of sleepless nights for the staff to get working in time for the game’s planned release date. He summarizes the experience as one that caused undue amounts of stress, illness, and reduced productivity, but was ultimately something that had to be done to get the game up to the company’s high standards.