(Of course this is no game discussion but still a project game tweaking/commenting because otherwise --- Helvetica 's Guideline
https://www.shrinemaiden.org/forum/index.php/topic,1364.0.html ---
https://www.shrinemaiden.org/forum/index.php?board=6.0 for " Help Me, Eirin! discussion, official or unofficial " or to
https://www.shrinemaiden.org/forum/index.php?board=10.0 for " All Touhou game
Akyu's Amazing Arcade - Games that are not Touhou-related ")
...I have not considered making any new, updated, or alternate versions of this game unless the first one didn't work, speaking of which, when I tried playing using google chrome it didn't work, though that's not what I normally use. I'm already working on a new game right now, one that I believe should be much better, possibly by the reasoning that it can't really be much worse.
On my end It seems meant/optimized for Firefox & Mozilla Browsers but it does work fairly smoothly for Google Chrome & Chromium as well .
My Google Chrome for Desktop PC has Java Permission Activated(Default) and the Latest non-beta Browser Release " Version 75.0.3770.100 (Official Build) (64-bit) " .
Though there are 3 Bugs (1.Fixed&Always; 2. by In-Game Player-Actions if Executed ; 3.Occasionally by Player Reloading of Game-Window) encountered so far that I am going to describe with their Player-End Solution and Occurences increasing the Bug-Risk ; CAPSIZED CHARACTERS will be the Better Highlights+Comprehension :

:wikipedia:
1. (Fixed "Demo")
Completing the "Demo" and and seeing the ( Forebonding ) Ending Scene locks any command(Esc;Space;Click;M;S;Unlisted) and (SOLUTION)needs a RELOAD or OPEN-CLOSE or BROWSER TAB-REOPEN.
Nothing could decrease/increase the Bug-Risk.
2. ( By Player-Actions : if Executed "Intruder Minigames")
Making the Aki Sister you chose go completely off screen during "Intruder Mini-Game" and keeps pushing for a bit she DISAPPEARS TOGETHER with her Danmaku which CANNOT BE FIRED ANY LONGER until (SOLUTION) , take not not everything from Player Shizuha or Minoriko REMAINS INVISIBLE,you MANUALLY TRY AND SUCCEED TO ALIGN AND GET CLOSER to the Intruder's DANMAKU WHILE WAITING OUT IMMOBILE FOR A BIT for them to HIT YOU TILL HEALTHBAR IS GONE->FAIL(UNBLOCK) THE MINI-GAME; after Fail Dialogue+Scene&Next Briefing the Character Sprte Player and Action-on-Screen RETURN TO WORK.
Certainly not disappearing completely or immediately coming back if so prevents it ,but USING MINORIKO (WASD KEYS ) make it happen faster.
3. (Occasionally By Player-Reloading of game Window Occasionally : " Keyboard Keys OCCASIONALLY Freeze after Reloading" )
SOMETIMES after RELOADING the Game Window ALL KEYBOARD INPUT(REGISTERED OR NOT)FREEZES while it is still OPEN [so no proper Esc->B to Quit or Closing->Opening "Index.Html (Minigame) ] and only clicking works ,EVEN IF THE GAME-WINDOW IS RELOADED ,BUT ( SOLUTION) OPEN-CLOSING OR BROWSER REOPEN TAB WORKS.
Multiple Reloading(more than an handful)during the Game increases Bug-Risk yet the Risk is still "Occasional".