Yeah, sorry for the length of the demo. I had what I thought was a small idea but I procrastinated a bit too long.
I've been working on an update as well as my other projects and I hope to have it out before the rating period ends.
Anyway, to your questions, the plants are meant to grow and wither but it may not be working properly. Initially there was a stress mechanic as well and watering your plants was a way to relieve some stress but I'll take a look at either removing the watering or working it back in in a meaningful way.
For the credits and post-credit scene, you'll want to walk to the right (east) side of the penthouse to the "office" area and interact with the note on the back of the filing cabinet. The note is facing the player so it's fairly easy to spot. This will play the credits, then immediately play the post-credits stinger, and then return you to the title screen.
Thanks so much for taking the time to play and comment! Sorry there wasn't more scares and "game" to be had lol