#shmup

Publisher Alliance Arts and developer Shanghai Alice Reprise, a team within Team Shanghai Alice dedicated to making classic games playable on modern platforms, have announced Touhou Project shoot ’em up remaster Touhou Koumakyou: New Classic – the Embodiment of Scarlet Devil for PlayStation 5, Switch 2, Switch, and PC (Steam). It will launch on September 10.

“There is a generation or two that has not had a chance to experience the Touhou classics,” said JUNYA from Shanghai Alice Reprise in a press release. “It has been 24 years since the release of Touhou Koumakyou, and the upcoming release of Touhou Koumakyou: New Classic – the Embodiment of Scarlet Devil will retell a beloved tale to brand new audiences around the world.”

Here is an overview of the game, via Alliance Arts:

Led by the original Touhou creator, ZUN, and a group of passionate creators, the beautiful bullet hell adventure gets a modern facelift with enhanced high-resolution graphics and rearranged music tracks composed by ZUN himself. Progress through the story with unlimited lives for a more accessible experience, or try classic gameplay for an authentic blast from the past with all original gameplay systems intact. A sudden scarlet mist surrounds the land of Gensokyo, and it’s up to shrine maiden Reimu Hakurei and her trusty magical companion Marisa Kirisame to discover the source.

Uncover the truth behind the mysterious mist while pummeling fairies, yokai and vampires with a steady stream of bullets and bombs. Unleash powerful Spell Cards while dodging deadly enemy projectile patterns from the enigmatic residents of Scarlet Devil Mansion. Touhou Koumakyou will be more accessible than ever with the addition of 11 new languages, including English, Japanese, Simplified and Traditional Chinese, Korean, French, German, Spanish, Russian, Brazilian Portuguese, and Italian. The Deluxe Edition includes a soundtrack highlighting more than 30 tracks, including both the original 2002 compositions and new arrangements.

Watch the announcement trailer below. View the first screenshots at the gallery.

Announce Trailer

English

Japanese

Korean

Simplified Chinese

BIRDCAGE vinyl release copies came in today, courtesy of Black Screen Records.

You can find links for this, the MiniDisc release and digital streaming here:

So you're making a bullet hell game. You've got 2,000 bullets on screen. You've got the player. You've got enemies. Every frame, you need to know: did anything hit anything else?

I have been thinking about this problem for months now. Years, actually. Because I am making a danmaku engine, and optimizing danmaku engines for any amount of crimes the user will put it through is my job.

So, this is the naive approach.

for each bullet: for each enemy: if bullet touches enemy: BOOM

2,000 bullets × 10 enemies = 20,000 distance calculations per frame. At 60fps, that's 1.2 million calculations per second. Your CPU is crying. Your laptop is a space heater.

Here's what we do instead:

Step 1: Every collision type gets a color based on bit flags

Enemy bullets = (1, 0, 0) ← red channel, bit 0 Player bullets = (2, 0, 0) ← red channel, bit 1 Player hitbox = (4, 0, 0) ← red channel, bit 2 Boss = (0, 0, 1) ← blue channel, bit 0

These are tiny values (like 1/255 brightness) so they're basically invisible. That's fine. We're not looking at this buffer.

Step 2: Draw everything to a tiny offscreen buffer with additive blending

When two shapes overlap, their colors ADD together. This is just what GPUs do. It's basically free.

Enemy bullet (1,0,0) + Player hitbox (4,0,0) = (5,0,0)

Step 3: Read the buffer and do bit math

pixel = (5, 0, 0) red & 1 = true → enemy bullet here! red & 4 = true → player hitbox here! PLAYER GOT HIT BY ENEMY BULLET

That's it. The GPU did all the "what's overlapping" work in parallel across the entire screen. We just read the results and check which bits are set.

The Original: TH03 on PC-98 (1994)

ZUN's Phantasmagoria of Dim.Dream maintained a separate 1-bit-per-pixel collision bitmap in RAM, downsampled to 2×2 pixel tiles to fit in just 6KB. Every frame, the game drew collidable shapes into this bitmap, then checked if any bits overlapped the player's tiny 8×8 pixel hitbox. The same bitmap doubled as the AI's "vision" of the playfield. To save even more cycles, rectangular hitboxes were drawn as horizontal stripes with gaps—since the player hitbox was smaller than the gaps, you couldn't slip through, and the game skipped 66-75% of the collision area for free. This turned an O(N×M) nightmare into a simple bitmap scan, running smoothly on an 8MHz CPU.

The Adaptation: Super Danmaku Maker on Modern GPUs (2026)

We're doing the same trick, but exploiting modern GPU capabilities. Instead of a 1-bit bitmap, we use an 8-bit RGB buffer where each collision type gets a unique bit flag (enemy bullets = bit 0, player hitbox = bit 2, boss = bit 6, etc.). With additive blending—which GPUs do essentially for free—overlapping shapes automatically combine their bits: enemy bullet (1,0,0) plus player hitbox (4,0,0) equals (5,0,0). We read back the buffer and decode the bit flags to know not just that a collision happened, but exactly what hit what. The GPU does millions of these additions in parallel, we just check the math afterward. Same philosophy as 1994, same O(pixels) scaling, but with 32 years of hardware evolution doing the heavy lifting.

2,000 bullets? Don't care. Same cost.

10,000 bullets? Still don't care. Same cost.

Cost scales with screen resolution, not bullet count

We can check an 80×60 buffer (4,800 pixels) or go full resolution (307,200 pixels) and it's STILL faster than checking every bullet against every enemy once you cross ~500 bullets.

The GPU approach has a fixed tax (reading pixels back from the GPU) but doesn't grow with bullet count. Traditional grows forever. It costs the same no matter how many bullets you cram in, and we use it for everything.

Bullets? Sure. Powerups? Of course. Player bullets hitting enemies? Naturally. Bombs? Why not.

The player has access to - 1, 2, 4, 8, 16, 32, 64, 128 - 8 colors of collision per color channel, for 24 different "collision categories", all of which run in constant time no matter what is colliding with what else, which is probably more than enough for your average Shmup or Danmaku.