Okay, to elaborate what this DLC does (I bought the whole pack while the latest patch was downloading so no idea what you'll see if you don't have any of it):
There's a separate DLC Mode in the main menu, next to AC and CS. Select it and you can pick any ship from the game and DLC you own (including the Murakumo), it shows a short blurb as well as promo art for the game that ship first appeared in. The Sega ships appear but are locked.
After that you get a stage pack selection, one per DLC game, a Taito Collection pack and CS Pack 1. The DLC Mode uses the rules of CS mode for gameplay, i.e. you select a stage that consists of multiple areas and bosses chained together with no branching, powerup rules and starting powerups vary. You cannot change the preset powerups but you can select any ship. There is no unlocking, all stages are selectable immediately. Of course you also don't earn CS mode points. There is no ultra-wide screen, no continues and no multiplayer. If you die you respawn with 3 armor. I don't think there's online leaderboards either.
The DLC packs each include three stages, all of which have 3+ areas and bosses and use the remixed old game BGMs. Note that they are still made from the same assets as CS stages, i.e. the same backgrounds, terrain, enemies, bosses, potentially arranged slightly differently but I'm not sure. The Taito Pack contains a few Defender, Scramble and single boss stages. One of the Scrambles includes two Thing bosses back to back... The CS Pack 1 is just a bunch of planets from CS mode, no apparent logic to their selection or order.
On the PC all three DLC ships had their own key bindings and they were complete garbage by default (look like random values picked from the save file), stuff like turn bound to 4, up to 6 and everything else unbound. I had to manually rebind them first after selecting each of the DLC ships.
All ships use the ARM system but some do not use gun or missile upgrades. Unsupported upgrades spawn grey balls instead. All three DLC ships seem pretty strong but simplistic. Here's what I know about them, perhaps there's more depth to them like the way the Murakumo has loads of features that aren't easy to notice:
Night Striker:
The gun only has one upgrade stage with the usual four bars to fill. It shoots blue balls straight ahead and when you hold any directional key launches homing shots akin to missiles but they home pretty badly and always at the closest enemy which might be outside their turning range. I have no idea why that attack stops when you let go of the arrow keys. If you move vertically and your car tilts two shots appear on top of each other, I think they normally overlap so you don't see them.
Missiles are fired as its burst weapon. They can upgrade in three stages (presumably more missiles each) using the green powerups. Holding the missile button launches a swarm of (badly) homing missiles diagonally with the same issues as the homing shots. The car seems to be invulnerable while shooting these. They're absurdly good for dealing with large clusters of small enemies as long as they are in front of you, if enemies get behind you the missiles can turn the wrong way and hit nothing.
Metal Black:
It takes no attack upgrades. The standard shot is two tornado-like projectiles with some distance between them. Their strength seems to depend on your burst gauge.
Tapping burst makes the ship emit an AOE lightning effect until you tap again, this is great against crowds. Holding burst emits a large laser forward. This laser can counter-burst with no timing needed, like the Murakumo. The burst meter does not recharge as normal, instead some enemies drop items that refill the gauge. These seem to move randomly, almost like they're carried by a current but stay on the screen for a while.
Rayforce:
It only accepts attack upgrades. The main gun has three stages, the second stage counts as a wave (piercing) and the third as a bullet (cancels bullets). Attacks are straight, a single projectile that looks like a bunch of beams.
The secondary attack is a homing laser, normally you have a lock-on area in front of you, enemies that fly into it are locked onto. Tapping the laser button launches homing lasers at all of them. Holding the laser button fires as soon as something is locked and continuously attacks but gives less score (tapped lasers have a 6x multiplier). Holding also expands the lock-on area. There's no limit to the use of this laser, it can only lock on to a certain number of targets at a time but can be fired as much as you want.
Attack upgrades turn into red tetraeders and move differently when you play the Rayforce ship, they seem to move more towards the center of the screen so they're easier to pick up than the regular powerups of the game.
Personally I found this a bit disappointing, I like my ships with more depth to their abilities and these don't seem to offer as much as the default ones. The stages just feel like more of the same without any of the structure of the other modes.
