Released last summer, Teenage Mutant Ninja Turtles: Shredder's Revenge is another example of nostalgia done right. The core beat-'em-up aspects that made the original arcade games so good remained, but the added tweaks like a six-player mode, individual endings, and even the ability to come up with attacks via a meter made it an equal to those games. It's a title that didn't need DLC to be great but also a game where extra content wouldn't be turned down, either. A little over a year later, we're getting that extra content with the Dimension Shellshock DLC.

There are two main components to this new part of the game. The first is Survival mode, which contains its own story. As the Turtles and their friends are celebrating their latest victory against Shredder and the Foot Clan, a dimensional portal opens up in their sewer home. Their friends from Dimension X, the Neutrinos, come through and inform them that Shredder has been stealing the crystals that power dimensional travel so he can rule the worlds in various dimensions. With no time to waste, the turtle brothers and their friends jump through the multiverse to collect the crystals and stop Shredder's latest scheme.

You and a party of six total players survive wave after wave of enemies, beating them up to obtain enough crystal shards to proceed to the next dimension. There are five different dimensions to travel through, from a classic arcade setting to the far future, a trip to the home of the Foot Clan, ancient Edo populated by anthropomorphic creatures, and even a throwback to the black-and-white Mirage Comic days. Defeating each wave opens a portal that changes the background of the current dimension you're in and gives you the opportunity to select one of two random rewards for moving on. Some of those rewards are extra shards, with bigger payouts coming from tougher levels. Others include standard stuff, like a full health refill for the next round, but the various augments make things more interesting, as they range from gaining speed when your combo count goes higher to taunting that teleports you to a different part of the screen — and even taking on the form of a big boss until you take on enough damage.

The various power-ups make this mode fun, since the wacky combinations make the solid combat even better to work with. The various backgrounds are also a great motivation to keep playing, as there's plenty to take in for a big TMNT fan. It's more apt to call this a roguelike rather than a survival mode, since completing gems grants buffs like more health or an extra life, so you can continue your run after getting knocked down. The presence of a story pretty much seals the deal in making this a mode you'll want to play often, especially if you aren't the type to get invested in leaderboards. The good news is that local and online cross-play are still supported, so the mode doesn't feel pared back when compared to the main game.

The second component is the addition of two more characters to the roster. The first is a guest character in the form of Miyamoto Usagi from Stan Sakai's Usagi Yojimbo comic series, someone who has also made an appearance in both the comics and animated series on occasion. The second is Karai, a character from the 2003 animated version that started as a villain but later became an ally to the turtles.

Compared to the rest of the roster, these two are stronger on paper, as they have a minimum of two stars on all stats, with Yojimbo getting three for speed and Karai getting three for power. This doesn't come through during gameplay, as the power differences aren't felt, whether playing solo or in a group. The real differences come from their different play styles, as Karai can dash around the screen swiftly, and her special move sends out clones of herself in both directions for a good distance. Meanwhile, Yojimbo feels like a more sword-focused version of Leonardo, as all of his attacks use his katana with the exception of his throw. Compared to the turtle leader, he doesn't have the range, but his speed with executing any attack makes up for it.

Their inclusion in survival mode is great, especially with the background tie-in to Yojimbo's home of Edo, but having them both be playable in the Story and Arcade modes is just as good. Those looking to see them in cut scenes will be disappointed, as they've been given the Casey Jones treatment where they are absent in all of them. However, they do have their own endings and are immediately playable instead of needing to be unlocked if you're starting the game fresh.

Even if you don't pick up this DLC pack, you get something courtesy of the accompanying patch: color palettes. There are a few fun ones, such as the old black-and-white color scheme or the pea green one from the Game Boy days, but fans will be more enamored with the various shades of green that reference the various TMNT incarnations over the years, except for the latest "Rise of the Teenage Mutant Ninja Turtles" series and the "Mutant Mayhem" movie. It would have been nice to see actual text telling you where each color scheme is from, but that's a very small nitpick.

Teenage Mutant Ninja Turtles: Shredder's Revenge Dimension Shellshock DLC is a well-thought-out piece of DLC. The roguelike nature of the survival mode is neat thanks to the various backdrops that are rendered in the modern pixel style and the various powers that tweak the combat for the better. The bonus characters are awesome to play, as they complement the roster without feeling overpowered as their stats would suggest. For those wanting to return to the game after a year or playing it for the first time, the Dimension Shellshock DLC is worth adding to the game experience.

Score: 8.0/10