This is a very clever game. But there's a good chance that you'll experience its cleverness only in a very passive way, because the game withholds a "secret" from you until you either type SECRETS (which isn't spoilery) or look at the second of the two in-game walkthroughs by typing WALKTHROUGH TWO -- but please don't actually do that!
If you do peek at Walkthrough Two, you'll be spoiling what would otherwise have been a whole new challenge, which is to try to solve the game using a secret vocabulary -- a vocabulary which is more restricted than that of the conventional solution (WALKTHROUGH ONE). Information about the nature of the secret vocabulary won't spoil the game, but I've still chosen to hide that information in spoiler-tags in this review.
I suggest that you first solve the game conventionally; then come back here and read the hidden text below; and finally try to solve the game again, but this time using the secret vocab only.
(Spoiler - click to show)The game can be solved using the names of certain objects as verbs. One obvious example involves the IRON: not only can you TAKE IRON (noun usage), but you can also IRON SHIRT (verb usage). There isn't actually a shirt in the game -- but that's not the point. The point is that the player can use the word IRON both as a noun and as a verb.
So the challenge for your second playthrough of the game is to first determine which words can function as both nouns and verbs, and then to complete the game using only those words, and using each of them as both a noun and a verb at some point during your playthrough.