Finished the main story of
Going Under a few days ago. While I liked the game (More games need to let the player whack foes with whatever they can get their hands on), I don't like the final boss nearly as much.
First, the boss arena is literally a square with nothing in it - the remains of an exploded rooftop meeting room. This also means that the only weapons you get (besides a sword you start the final boss with, that can break like every other weapon) are the ones enemies drop, which can be anything from pickaxes (moderately effective but slow) to body pillows (rather fast but short-ranged and weak). Occasionally drones show up, sent by your allies to provide some other weapons, like a giant drill, or a vending machine turned into a launcher (the cans it shoots explode like grenades). While this mitigates the issue somewhat, such drops are somewhat rare.
Second, while you can choose a skill you've endorsed (used for long enough) to start the level with, choosing a mentor has no effect - and even if it did, several mentors have skills that wouldn't apply in the single-arena gauntlet, such as Tappi's increased money gains or Ray's ability to buy items the player can't afford. More of a minor irritant, but still something that did irritate me.
Third, healing is very scarce. Occasionally, allies drop a toasted Jobwich, which heals for a full heart (by default, you start with six at this stage, and getting hit removes half a heart). This happens very rarely and no other healing items are provided besides the possibility that a foe
might drop a self-care app (which requires you to stand still to use, which makes them vulnerable to losing the heart they healed).
Fourth, occasionally allies will drop a skill into the arena for you to pick up. Several skills use mechanics not involved in the final boss fight, such as Intimidating (which knocks foes down when Jackie enters a room) or Cubicle Rewards Member (which provides cash upon opening cubes). As stated before, this fight takes place in a square arena where there are no shops or new rooms to enter.
Fifth, and the issue I found the most irritating of the lot... Once you've survived the gauntlet of enemies long enough, an ally drops an app that you need to use. The nature of the final boss means that they're impossible to damage in the physical world, so you need to use the app to enter a special space where you can harm them. This space is a circular arena devoid of objects of any kind. The final boss will block all attacks, so you must wait for them to perform an attack so you can dodge away and punish it. After punching the boss enough times, the fight moves to its next phase and eventually the end. However, if you get hit before you damage the boss enough to move them to the next phase... The boss heals all the way back up to whatever HP they were when the phase started, and you are kicked out of the special space to survive another gauntlet of enemies. This essentially means that if you make one mistake, you lose all your progress.
I did eventually beat the boss, but it was rather frustrating. Again, though, I'd still recommend the game.