Pretty great homage. I'm very much a fan of the bigger map and multiple endings. It manages to both be faithful to its source material and allow itself to be original with the added content.
That being said, there are a couple technical issues though. During my first playthrough, my inventory overfilled and not only did I lose the match I picked up, the next item I clicked on disappeared when I tried to use it. The other time, I grabbed the cookie from the vending machine t̶o̶o̶ e̶a̶r̶l̶y and randomly got stuck in the dispenser screen with no back arrow. And when I tried the alternate ending with Richy, I could not seem to interact with any of the changed environment. Clicking on Richy for some reason teleported me to the electric outlet in Mrs. Sleep's room and after returning to the gym, everything was restored back to before, except I was still missing the items I used before.
Edit: So just for future reference, yes, the library minigame has to be completed to get the main ending. Best method I found is having the cursor in the center of the screen. The speed and direction is random and it might take a few tries, but the targets always cross around the middle area. Hope that helps.