Abyss Soul Lotus/Strategy
The scoring system in this game revolves around the border release system. Here we give a brief rundown of the mechanics. For a detailed explanation, please see the Manual here: Abyss Soul Lotus/Translation.
Grazing takes a backseat to the border system in this game. Points are directly given at a flat rate of 1000 points per bullet grazed. This isn't a lot, but can still be significant over the course of the entire game.
Your PIV is shown in the usual place in the right HUD.
There is a global multiplier applied to all blue point items when collected. It is usually not shown, but when you POC a small tooltip will show up showing the value of the items collected and the multiplier, if greater than 1, e.g. "20000" (multiplier is 1.0 and hidden) or "50000 x 1.1". This global multiplier resets to 1.0 every stage, and is increased by chaining (see section below).
Border Fragments are the diamond-shaped items you obtain from canceling bullets, whether from killing enemies, starting or ending spellcards, or the stage ending. They come in three variants: colorless, colored, and golden, each having more value than the last.
Because canceling is so crucial to scoring in this game, every time you kill a stage enemy that cancels bullets, a small number showing the number of bullets canceled will flash next to your character.
The lower left bar is the Border Protection Gauge. It fills when you obtain Border Fragments from canceling bullets, up to level 3. Each level grants a life fragment, but only the first time you reach that level until you release again. (This prevents you from getting infinite lives just from ping-ponging between level 2 and 3). Each level also protects you against one hit. Additionally, note that as your level increases, filling the gauge takes more fragments.
The lower right bar is the Border Fragment Multiplier Gauge. It is also filled by collecting Border Fragments. The gauge as well as the multiplier shown beside it refer to the multiplier that will be conferred when you switch shots by pressing the C key. Once you press C to switch shots, the filled gauge quickly empties and the multiplier drops back to zero. The maximum amount is 3.0.
Switching Shots and Border Fragment Multiplier
In this section, "gauge" refers to the bottom right bar, the Border Fragment Multiplier Gauge.
Pressing the C key at any time switches between your shottype's two shots. The multiplier built up in the gauge begins applying immediately and drains briskly back to 0. Thus, a naive strategy to maximize your multiplier is to wait until it fills up to 3.0, then switch shots and begin accumulating for the next switch, as leaving it at 3.0 unused is a waste.
Some shot types also have a secondary effect upon pressing C. Reimu B and Marisa A receive a power boost depending on how full your gauge is, the gauge influencing the power of the boost for Reimu B and the duration of the boost for Marisa A. Marisa B will receive an extra punch from Okina related to the shot you switched away from, as well as invincibility frames (very useful), the caveat being that both only happen if the gauge is full.
What exactly does this gauge multiply? It's a multiplier on how fast the left gauge (Border Protection Gauge) fills per Border Fragment you receive. Thus, it might be wise to save a multiplier if you know you have a huge cancel coming up, then switch right before the cancel. Doing this right can fill your left gauge from nothing to maximum in a very short time, giving you another release.
A border release can be performed when your left gauge reaches level 3. Unlike HSiFS, a release is a prolonged process consisting of activation, sustain, and reflux. You can think of it as a HSiFS release with a PCB border following it.
On activation by pressing X, all bullets on screen are canceled as usual, then a ring will appear and cancel any subsequent bullets around you. You also gain a short time of invincibility. Unlike usual, bullets canceled by this ring do not produce Border Fragments, but snowflake items that increase your PIV. This is the only way in the game to increase your PIV. Different characters have different ring properties - Reimu and Yukari's ring is smaller but lasts longer, while Marisa and Okina's is extremely large but only lasts a brief moment.
Note also that activating a border during a spell card fails the spell, but there is a short window after the spell sound effect and portrait appear in which you can still release without failing the spell. From experimentation, it seems that releasing any time before the spell bonus appears in the top right corner is safe. This means you can perform a release as a spell is beginning and cancel some of the spell's bullets to gain PIV without failing the spell.
Regardless, after the ring disappears, the sustain stage begins. During the sustain stage, a timer appears above your head. During this time, all point items are auto-collected. Note that unlike PCB, you are not invincible during this time. This leaves you highly vulnerable since all your shields were just used to perform the release. Additionally, this timer does not tick down during spell cards. Capturing a spell during a sustain rewards a sizeable amount to your left gauge, aiding you in getting combos (see next section).
After the timer ticks down all the way, the border ends (known as Border Reflux) and the screen is cleared. Like PCB, you may manually break the border by pressing X, but note that doing so fails spell cards. Unlike PCB, you do not receive invincibility frames when a border ends.
Another crucial way to increase your score is by chaining borders. This is done by getting back to level 3 before your previous border timer runs out, then pressing X again. This chains the end of your first border with the beginning of the next one. When doing this, the regular colored fragments spawned during the initial screen clear will instead have a golden coloring. These golden fragments will increase the global multiplier on all blue point items for the rest of the stage.
In summary, aim to increase your PIV by releasing as often as possible at opportune times (many bullets on screen). At the same time, aim to increase the global multiplier by chaining your releases together. Both of these rely on filling the left gauge efficiently, which relies on appropriate use of character switching and the right gauage. With how varied each shot type is, it should make for a very rich and interesting scoring scene. Good luck!