Yesternight is an extremely sparse game. Room and object descriptions are only a few words, or outright absent. It’s also very short, with only two simple puzzles, and no plot except the player’s natural motivation to go forward.
What’s there is a charming, fairy-tale adventure; but there’s so little of it!
The main flaw of the game is the painfully lacking implementation. There is no scenery at all: if a game says “You see a grocer” in a grocery store, it should know the word “grocer”. The puzzles suffer badly from guess-the-verb syndrome.
The game’s English is poor. In particular, it omits many articles. One verb is used in a non-standard way, which affects the solution of a puzzle. I’m unclear if this is a deliberate stylistic choice, a limitation of the engine, or the author having difficulty with English.
Walkthrough and map (major spoilers)
For the author
Have you considered writing this game as a graphical, point-and-click adventure instead? This would lend itself much better to the narrow options.
Alternately, have you considered a different parser (e.g. Inform or TADS), that comes with sensible responses to a lot of common verbs?
If you want to focus on AdvSys, try playing The Sound of One Hand Clapping, a fleshed-out game you can use to get more ideas.
If you’re having trouble with English, do feel free to ask for copyediting/proofreading help. Come to any of the English-language IF Discords, I (and probably quite a few others) will be happy to help.