I had quite a bit of fun thinking this one up. Again, only the words in block-quotes are relevant to the puzzle.

A sequence spirals down and out, following the clock
Starting with the first mail item a password you'll unlock

Moving like a knight (not right) you'll want to first extend
Almost there, you look up (take a hint, man!) and then go home again

Fire two shots to the north to hit a curvy groove
Then like a bishop off to tea it's time to make a move

You stretch the furthest that you can to reach the leftmost end
But when you're there, something nearby drives you round the bend

There it is! Tall and upright, bold as it can be
You take its head, you take its feet! Now, listen close to me

By now you've done all that you should; the answer's clear at last
So tell me, as you say the word, wasn't that quite a blast?

Hint #1:

A sequence, I stated, but what could I mean?
Best not to move on till this meaning you've seen
Carry out each step from beginning to end
Don't forget now: I'm a punny sort of man

• Move to recycle bin? :D – WeShall Oct 10 '16 at 2:04
• @WeShall: Say what? – Xenocacia Oct 10 '16 at 2:08
• As I was reading through, i got clues like (not right) = on left side, first extend = expand something, go home = back to home screen, two shots = double click, leftmost end = close menu on linux & mac systems. Implying something related to computers. – WeShall Oct 10 '16 at 2:13
• Ah, right. Nope, this has nothing to do with computers. Nice try, but try again! – Xenocacia Oct 10 '16 at 2:16
• something to do with chess? move like a knight, (not right) you'll want to extend, that means two forward and one left, because you extend forward first? 'like a bishop' is diagonal, but I'm not sure about the parts with clocks and curves and bends. – MMAdams Oct 10 '16 at 3:06

A PASSWORD (or the sloppier, APASWORD)

A sequence spirals down and out, following the clock

Thanks to Namisca, but using the alphabet instead, the sequence spirling down and out/clockwise is

Q R S T UP E F G VO D A H WN C B I XM L K J Y        Z

Starting with the first mail item a password you'll unlock

I don't really get this one, but 'A' seemed like a good place to start. Maybe mail is handled alphabetically? OP EDIT: as pointed out, "mail item" = letter.

Moving like a knight (not right) you'll want to first extend

Moving 2 left is the 'O', but it didn't help me so I ignored it.

Almost there, you look up (take a hint, man!) and then go home again

1 up is the 'P' and home again is back to the 'A'. I took both because they worked for me.

Fire two shots to the north to hit a curvy groove

2 up is the 'S' (which is the only reason I stuck with this because it fit the clue so well). Maybe take 2 of them because "two shots"? but that feels like overusing the two... OP EDIT: Indeed, "a curvy groove" refers to 'S'. Two shots is to take it twice.

Then like a bishop off to tea it's time to make a move

Thanks for whoever and the other guy for confirming that this is southeast. It's not clear how far to move, but it's either 'G' or 'W' and 'W' works better.

You stretch the furthest that you can to reach the leftmost end

Leftmost from the 'W' is the 'O'. I liked it. I kept it.

But when you're there, something nearby drives you round the bend

I really thought the 'N' fit the "bend" best, but rounding it is the 'C', and its head and feet are 'D' and 'L' which I didn't like. So I went round the 'P' to the 'E' and took its head and feet (in that order) - 'R' and 'D' OP EDIT: to be "driven round the bend" is to get angry, or "see red".

OP EDIT: There it is! Tall and upright, bold as it can be

Beside 'O' where we are now, the word "RED" can be seen vertically.

OP EDIT: You take its head, you take its feet! Now, listen close to me

Take the top and bottom of "RED" to get "R" and "D" in sequence.

OP EDIT: Hint meaning

The first letter of each line spells out 'ABCD' as a hint to get thinking about the alphabet as a sequence. The rest of the lines are just to be taken literally.

OP final comment:

I did tell you guys from the beginning that you would unlock 'A PASSWORD'. :)

• mail item probably means 'letter'. therefore A is the first letter – MMAdams Oct 12 '16 at 18:49
• ah, makes sense. and is punny – user1566694 Oct 12 '16 at 18:57
• +1, I think you've got it. Thoughts - the extension of the knight is to direct the type of movement and not necessarily land you on a letter, otherwise you'd end up with L or R. As for the bend part, interestingly, the letter at the "bend" is the same shape you make when moving left and around the bend. Good job! – Steve Mangiameli Oct 12 '16 at 19:27
• Congratulations! There are quite a few clues that haven't been fully interpreted, though. Regardless, I will award the bounty to this answer. For the rest of the clues, should I edit this one or post my own solution set? – Xenocacia Oct 13 '16 at 0:53
• @Xenocacia Personally, I would edit this answer with OP Reason where clues were missed, or something like that. – dcfyj Oct 13 '16 at 14:02

Some thoughts and ideas.

1 . We draw a square with the word SEQUENCE, in a clock-spiral pattern. The password will be drawn by the letters on which we stop.

S    E    Q    U
U    E    N    E
Q    E    C    N
E    S    E    C


We start at the bottom S which is the start of the second word. First letter is S

1. Knight on a chess move in a L shape. We want to extend first so we move top, then left. We thejn take the letter in the case above, and the start one. U S S

2. going up by two then bottom diagonal (bishop + 5'oclock tea explained in another answer). E C

3. we got the the leftmost letter then grab one of the surrunding one. (i pciked the Q because it bends ?? ) E Q.

4. We strip off the first and last letter.

SUSSECEQ --> USSECE.

My brain hints that the intented answer is another word but i can't make it work yet.

SUCCESS

• Collecting the letters along the bishop's movement path picks up the extra letter you want, does it not? I just don't see anything that justifies the starting point you chose; it should have something to do with "Starting with the first mail item". – Rubio Oct 12 '16 at 14:30
• @Namisca: you're definitely thinking along the right track, but did you look carefully at the hint, as well as the main puzzle text? :) Every line has one or more meanings you have to make use of! – Xenocacia Oct 12 '16 at 14:42
• 'a sequence spirals down and out, following the clock' perhaps your square is wrong? Down and out suggests that the letters start going down and continue clockwise and 'outward' whereas yours start to the right and then turn clockwise and inward. – MMAdams Oct 12 '16 at 18:47

My thoughts are

these are instructions to literally spell out a word

A sequence spirals down and out, following the clock Starting with the first mail item a password you'll unlock

starting on the clock when mail is delivered (depends on locale), likely draws the letter 'C' in some rotated form

Moving like a knight (not right) you'll want to first extend Almost there, you look up (take a hint, man!) and then go home again

a knight moves in an 'L' shape; to extend meaning to the side (left) then up, but also going home making a trangle shape? perhaps something resembling an uppercase 'A'?

Fire two shots to the north to hit a curvy groove Then like a bishop off to tea it's time to make a move

two lines up and a diagonal line to '4' oclock to make an uppercase 'N'?

You stretch the furthest that you can to reach the leftmost end But when you're there, something nearby drives you round the bend

perhaps a capital 'D' on its flat side?

There it is! Tall and upright, bold as it can be You take its head, you take its feet! Now, listen close to me

an uppercase 'I'? or 'Y' seems to fit better with the other letters

By now you've done all that you should; the answer's clear at last So tell me, as you say the word, wasn't that quite a blast?

CANDY?

• That's actually a pretty decent attempt, but I'm afraid that the answer has little to do with the shape of alphabets. You are warm in thinking that these are instructions to arrive at a word, though. – Xenocacia Oct 10 '16 at 7:33

Is this a

piston in an engine?

A sequence spirals down and out, following the clock

A (four-stroke, others too of course) engine works in sequences like clockwork

Starting with the first mail item a password you'll unlock

The sequences in an engine follow each other always in the same order. First the fuel-air-mixture needs to be "received" before going to the next sequence.

Moving like a knight (not right) you'll want to first extend Almost there, you look up (take a hint, man!) and then go home again

The piston goes up and down

Fire two shots to the north to hit a curvy groove Then like a bishop off to tea it's time to make a move

At least in a four-stroke engine with 4 valves per cylinder there would happen "two shots to the north" in one cylinder from the two exhaust valves when the piston is going up, and after this the piston goes down again. Some might find the engine sound a kind of groovy.

You stretch the furthest that you can to reach the leftmost end But when you're there, something nearby drives you round the bend

"Leftmost" gets me a bit confused.. Maybe in a boxer or a V-shape engine the pistons move left/right in relation to the ground but of course the cylinders are then also inclined. The crankshaft of course does rotational movement where there is also left and right involved. "Something nearby drives you round the bend" - the crossrod connects the piston to the crankshaft limiting and timing it's movement even though the cylinder wouldn't be firing.

There it is! Tall and upright, bold as it can be You take its head, you take its feet! Now, listen close to me By now you've done all that you should; the answer's clear at last So tell me, as you say the word, wasn't that quite a blast?

Again, the piston goes up and down. The fuel-air mixture is fired in an engine when the piston is in the upmost position (well just a small moment after this actually) and that will be a small explosion, quite a blast.

• You might want to edit that to put it in spoiler blocks. – Xenocacia Oct 10 '16 at 5:51