Set a thousand years after the events of the previous game, Nina and Ace awaken to a world completely remade and ruled over by the Synthetic Mind. Somewhere along the way, humanity lost their freedom, hopes, and dreams. The contractors must now jump and shoot their way through this new reality, on the chance that they may save what remains.
Unlike its predecessor, the game offers two main modes of play:
- Standard: The normal roguelike, Final Death Mode, where the main levels are played in a random order, with the player losing all upgrades and progress upon death, though the player can buy permanent upgrades with 'Memoria' and 'Potentia' currency back at the HQ.
- Mega Mode: A mode that removes all roguelike and Final Death Mode elements, with three save file slots available. All main stages can be played in any order, with increasing difficulty based on 'Normal', 'Bold', and 'Defiant' tiers. Levels are still randomly generated, but are based on a seed that is generated upon a new save file that then stays the same for that particular file. Like with Standard mode, there are permanent upgrades that can be bought with 'Memoria' and 'Potentia' currency that affects all and future Mega Mode save files.
The game was released on Steam in Early Access on February 17, 2021.
30XX provides examples of:
- Ability Mixing:
- Nina's Power Fusion ability lets her augment one power with another to get one that has properties of both. For example, augmenting the Rending Whirl (creates a tornado where Nina stands) with the Negating Pulse (erases projectiles in a small area) results in a tornado wall that deflects some projectiles.
- The changes to how Core Augments work allows one to mix and match them to stack their effects. For instance, you can equip Oxjack's Blitz and Dracopent's Bound at the same time to enable air dashing and Double Jumping.
- A.I. Breaker: Legacy's weakness is a rare example of this trope being intentional game design. In its base pattern, Legacy takes "turns" moving with its Shapes; they move into their new positions, and then Legacy moves. Freezing the shapes with Crystal Wave prevents them from moving on their "turn", which also freezes Legacy. Augment Crystal Wave with Rending Whirl, and Legacy will be stuck just sitting there while Nina pounds away on it with her Buster.
- Each stage starts with a section in which you can check out its gimmicks without much danger.
- Each stage has at least one common enemy or hazard similar to an attack the boss will use. In Highvault, for example, one of the most common obstacles is a box-like enemy that fires tornados. The enemy telegraphs and fires using the same timing as Hoot Omega's Rending Whirl.
- Balance Buff:
- Boss weapons in this game can now be collected in addition to the stat boosts you get at the end of stages, giving a very needed buff to them compared to 20XX, where most players would often just skip the weapons for stat boosts.
- Core Augments have their own inventory now, where you can turn them on and off whenever you like. Under this new system, armor set cores are no longer mutually exclusive with one another. You can collect the same part from two or more armors and activate them together to stack and combine their effects. The sheer flexibility more than makes up for the removal of the previous game's Set Bonuses.
- Band Land: Echocave is a mix of a musical level and Crystal Landscape, as both crystals, gigantic speakers, and gigantic crystal tuning forks are strewn throughout.
- Cherry Blossoms: Cherry blossom petals fall once you defeat Zen Primus at Burning Temple, affirming your victory.
- Creepy Cathedral: Penumbra takes place in a church with gigantic stained windows. Its boss, Absolution, looks like a demented preacher.
- Divergent Character Evolution: Nina and Ace are now much more distinct characters. In 20XX, their only differences were the main weapons they could equip. Now, they gain different powers and have unique mechanics, like Ace's power surge and Nina's fusion system.
- Eternal Engine:
- Clockzone is a, well, clock-tower-themed area filled with perpetually moving gears.
- Dustria is a gigantic factory filled with industrial equipment and robotic workers all looking to take you out.
- "Get Back Here!" Boss: Hoot Omega flies away when damaged enough, forcing you to race through the stage to get back to them.
- Indy Escape: The first half of the Burning Temple miniboss involves you being chased by a giant flaming spike wheel down a narrow corridor full of enemies and obstacles, until you eventually run into a larger room and fight it there properly.
- Last Chance Hit Point: The auto tank grants you some health when you take fatal damage. However, it starts off empty; you need to fill it with health pickups first, and it only works once per run.
- Lethal Joke Item: The Toy Beam weakens Nina's normal attack and adds angle variance to her shots. However, it also essentially costs -5 Core Points to equip, giving you room to equip other Core Augs.
- Level Editor: There's a level editor, the same one the developers use, which lets players create their own 30XX levels and share them around the world.
- Nerf: Main weapon stat ups are much rarer than in the previous game, making the old strategy of dumping special weapons and energy to focus purely on buffing the main weapons much harder to pull off.
- More Dakka: Nina's Buster upgrades are treated as Core Augments, and thus can also be activated together to combine their effects. Most of those upgrades add to the total number of Buster shots that appear on the screen every time Nina fires. Forkalator and Scatterblast upgrades add more shots fired at once in a larger arc. Retrobeam adds a single shot that fires backward. Vertibeam adds single shots firing up and down. Star Beam fires in all four cardinal directions. Getting lucky with Buster upgrades on a Standard run or Mega Mode file can result in Nina filling the space around her with yellow Buster spam.
- Power at a Price: Prototype Augments return, although this time around, the advantage and disadvantage they grant are combined randomly.
- Retraux: The game has a new pixel art style that is closer to that of the Playstation Mega Man X games, owing to its retro inspiration.
- Rocket Punch: Capital Punishment has three jet-powered fists that can be used offensively or orbiting as a shield.
- Variable Mix: The Penumbra stage and boss fight segues between different parts of its theme depending on where you are.
- Wolfpack Boss: Lethal Tempo is composed of four parts working together. As you defeat each enemy, the remaining ones become fiercer with their attacks.
- Wutai: The Burning Temple stage is themed around Japanese architecture, complete with shrine gates and pagodas in the background.