Hello again! Ah, you are completely right, my apologies for the mix-up! Visual novel routing can be a bit of a maze sometimes even for the developer 😅
Let's get you those final endings:
For Scaramouche:
Please don't worry about the timed mini-game on Hard Mode! The timer is actually very generous (gives you a whole 90 seconds) and you literally just need to click on the bug right away. You have plenty of time, so absolutely no need to panic! You've got this!
For Flins (Ending 5):
I see! The grave ending actually changes depending on what you do earlier in the route. Since you got "Heavenly Hangout" (Ending 4), it means you chose "Is this a joke?" when looking at the creepy photo on the dresser.
To get Ending 5, you should choose "Something weird is going on..." (or just let the timer run out) at the photo in the hallway first. Then, visit the grave at night. Because of your earlier reaction, the scene at the grave will be entirely different!
For Tartaglia (Main Story Ending 3):
You are 100% correct, complaining gets you Ending 1 ("The Bait"). Ending 3 ("The Perfect Lure") is actually a highly hidden cross-story secret!
Since you mentioned you already got the bad ending with Dain in his Maslenitsa route, you meet the secret requirement.
Just play Tartaglia's Main Story normally. After the fishing mini-game, when you sit down for a snack, choose the option to "Check your phone". Because you have that specific Maslenitsa ending unlocked, a completely new dark secret scene will trigger instead of the normal text messages!
Good luck, and thank you so much for playing and trying to 100% the game! 🤍