The game will end REALLY FAST if you don't know what you're doing, so here's the gist of it:
1. Colored shapes will fall from the top of the screen.
2. Send up white blocks by clicking the screen, left click for slower blocks and right click for faster ones.
3. The game ends when you run out of health (The bottom bar) which is restored when blocks are destroyed.
4. Health drains slowly depending on how many blocks are on the ground.
5. Hitting a shape with a white block will light them up, when lit, they'll fall and destroy blocks of the same color that they land on.
6. When a lit block touches the ground or another of a different color block that's already touched the ground it'll go dark and make you lose health.
7. When a lit block touches another block of the same color in midiar, they'll both light up brightly and become "Active" (like in the above picture).
8. "Activated" blocks will fall to the ground and explode, destroying blocks of the same color they touch. Destroying blocks in this manner gives combo bonuses.
9. Blocks are immaterial until they reach the ground or touch a solid block - White blocks, blocks that have already touched the ground, and blocks that have been lit with a white block (And blocks that they touch. Activated blocks will only solidify blocks of the same color).
10. You can keep blocks in the air by shooting them, but active blocks will be destroyed after 3 hits, giving no health or points.
11. White blocks remain on the screen until they touch a block that's been lit or activated.
12. Circular "bombs" destroy all blocks of the same color, they keep switching colors until they are hit or land. Once the bomb goes off, the game moves faster for a short time.
13. The bunny girl that's in the background is Irisu, it's in your best interest to keep her happy.
Please don't spoil the story for the other players.
14. Obtaining high scores will make the game create little tidbits of the story in the game folder. Keep an eye on that "Photo.png" file as you keep going.
15. Achieving enough points will unlock "Metsu mode" which is equivalent of Touhou's Lunatic mode.
16. Take a closer look at the scrawls in the background of the game screen.
On the title screen, Clicking the game title will change the song. From the top the options are "Start", "Album", and "High scores".
Download link here, click the green rectangular button.English Patch Here, extract it over the game folder.
Since the game is Japanese, you'll need to set your region accordingly or use Microsoft Applocale.
NVIDIA GRAPHICS CARD USERS PLEASE READ.
You'll need to force anti-aliasing manually or else your game will crash and make your computer Blue Screen.