No, I don't offer a game for this CaveJam; it's a lot of work and I decided to improve my CaveJam game a little bit. It's also an opportunity for me to play other people's games (less sentences in English, so it's a bit easier for me).
For the keys and the key, I was simply suggesting that there should not be a default message as there is for other words in the singular and plural (>GET KEYS => "Can't take."). But these are details.
You are a professional and we have a lot to learn from you. Too bad your advice is scattered all over the various Adventuron jam forums.