The verb 'sew' does not seem to be recognized. Yet we have needles, cloth, cotton. But especially when you look at the cotton, it answers: For sewing. (I've been trying to sew up a bag, to pick up peas!)
This is quite disturbing:
> x mat: Got hole
> insert needles: No hole
(Of course, I tried to sew up the hole in the mat.)
A detail: you can enter the shop and the haberdashery by typing 'Enter shop/haberdashery', but you can't exit with 'Exit'. (Same thing for the stable, the chapel, and so on.)

Time passes...
Now I've got the bag, two treasured items and 10 score points.
Which I tried and was turned down:
> sleep hay
> empty bag
> sow peas

This is the price I pay for adding extra verbs that I didn't really expect anyone to use. Seriously, you are a great tester and I value your feedback. Comments below:

Regarding X DOOR and being told it's to the north or south, that was a conscious design decision to work around the two-word limitation. I tried a few other approaches before deciding on this one. As a keen adventure mapper, I like to know where exits go before I go there so that I can draw connections on the map. I would normally describe doors and their location in the description, but the two-word format does not allow a description. When you examine a door, I would normally give a description of the door and say whether it's open or closed. For example:

>X DOOR
It's a large wooden door with scuff marks around the handle. It's currently open/closed.

I think my compromise is a nice one, as it's player friendly and mapper friendly. The door description dynamically changes to tell you whether it's open or closed. The exit is dynamically hidden/shown depending on whether the door is open or closed. And you can still see what direction the door is in before opening it.

Regarding 'You can "saw", but not "cut", you actually can cut, but you need a knife. You can also chop, but you need an axe. The game tells you this. But you cannot cut or chop the object you're thinking of because they're the wrong tools.

Regarding messages adapted for plurals of ear(s), leg(s) etc. but not for key(s), the game originally had singular arms, legs etc. and you had to get two of each to get a pair. However, this was a bit tedious (for the player) and difficult to implement (for me), although I did have a very clever routine that magically combined two single objects into one plural object when they were together, but you couldn't separate them again. There are a few cases where you can still refer to the singular object and this sometimes provides a clue. For example, have you tried EXAMINE RULER or TAKE PEA? In other cases, if the player uses singular, I suggest using the plural and that avoids having to duplicate a lot of objects and a lot of messages just to account for singular and plural. Of course, an easy way out is to make the singular and plural synonyms, but then the responses may not make sense, particularly in a game that revolves around word play. Have you noticed that Igor usually refers to things in the singular? This is significant for things like the pea/peas, as you will know having completed the game.

The big difference with the key and the keys is that both can exist simultaneously, so it is not appropriate to suggest using KEYS when you use KEY because they are two different things.

Regarding the messages when playing the piano, this was another conscious design decision. There are three tunes and it cycles through the tunes in sequence. The first two responses are teasers to encourage you to try again so that you hear all three tunes. The player does not know how many tunes there are or whether they're played in sequence or at random, so the "That's enough." message is to indicate that Igor's repertoire has run out, but that doesn't stop him playing again if he wants to. In fact, we want him to play again after getting 'you know what' so that he can see what it is that he got, as that is significant further on in the game. Incidentally, when Igor plays the broken piano, the cycle restarts so that he can hear the tunes that he's already played (assuming he's played them) to see what the differences are. It's subtle, but clever within the constraints of the two-word rules. At least, I think it is.

Regarding "Igor carry: Nothing.",  that's an Adventuron bug. My custom system message for this is actually "nothing" (lower case). I told Adventuron about it, but he's probably forgotten to fix it.

Regarding some extra messages for the crucifix, pins, cloth, saw etc., a couple of these are red herrings that are there for atmosphere or realism and the others have served their purpose and have no further use. I have to draw the line somewhere. Otherwise you could get an inventive player that wants to break the saw and wrap the cloth around the broken piece of saw to create a screwdriver to unscrew the crucifix so that they can scratch their name on the back of the crucifix with the pin. :-)

Regarding the receipt, there was no change recently, but I think I changed the wording on it and added the sign in the dry cleaner after version 0.0.0 to make the association clearer, not that it really needed it. The receipt is not yours, but the attendant doesn't really care. He only cares that you've got a receipt to collect something.

Regarding all the other things, I'll add them and do another build during the weekend. Once again, thanks for the feedback and the interesting discussion. I'm hoping that you submit a game yourself, because if you do and you're as careful with yours as you are with mine, you could be on a winner!