'Stranger Things' Season 2 is full of references to one classic arcade game

Ahead of the release of Stranger Things Season 2, the titles of the first six episodes were revealed, giving the world an extremely vague tease of what's to come. One of those episode titles is a reference to an arcade game from the '80s, and now we know why.

Warning: Stranger Things Season 2 spoilers ahead

The fifth episode, titled "Dig Dug," is named after the classic video game of the same name, and reveals something sinister lurking just beneath the town of Hawkins, Indiana: Tunnels.

Not just regular old tunnels though, Upside Down tunnels that play host to the horrible denizens of the Upside Down including weird tentacle things and abscesses that spit at passers by.

From episode five and onward, a handful of characters descend into the tunnels beneath Hawkins from the entry point that Jim Hopper dug in the middle of a pumpkin field in episode 5. But what exactly does all of this have to do with the 1982 arcade game Dig Dug?

Quite a bit.

In Dig Dug, players control the titular character Dig Dug as they dig into the earth and defeat monsters that have dug their own subterranean tunnels. Players earn points by killing the monsters in various ways, trying to earn a high score. In the second season of Stranger Things, people enter the tunnels to kill monsters, albeit more to save lives than to earn points.

A Dig Dug arcade cabinet was actually featured at the very beginning of the season in the local arcade where the kids gathered to play games and met their new companion Max for the first time.

The Dig Dug connection goes beyond tunnels and a cameo appearance, though. In the final episode, Mike, Lucas, Dustin, Max, and Steve enter the tunnels to lure the demodogs away from Eleven and Hopper while the duo attempts to close a giant gate to the Upside Down, some of them decked out with handkerchiefs and swimming goggles.

These swimming goggles are a reference to one of two monsters found in the game Dig Dug: pookas. Pookas are small, red creatures that hang out in tunnels and wear big goggles. It's a small nod to the classic '80s game that most people might miss.

The other enemy in Dig Dug, the fygar, also gets a shout out in the final episode. As Eleven is using her powers to close the gate between Hawkins and the Upside Down, the giant monster that just won't go away appears on the other side. The unnamed monster unleashes a flurry of fire at Eleven and Hopper, trying to stop them in their tracks.

That burst of fire is a reference to the fire-breathing attack that fygars use against Dig Dug, which kills him in one hit.

The only thing that would have put this over the edge is if Hopper or someone else in the tunnels used a bicycle pump to blow up a demodog or something — the preferred method of extermination in Dig Dug.