What is the conceit(s) in Hamlet's first soliloquy in Act I, Scene 2?

In poetry, a conceit is an extended metaphor. Certainly in Hamlet's first soliloquy, there are some metaphors, but, as a whole, the speech does not have a single, continuous extended metaphor.

If this helps, here are the metaphors:

First Hamlet compares himself to water or ice:

O, that this too too sullied flesh would melt,

Thaw and resolve itself into a dew

Then he compares the world to a neglected garden:

How weary, stale, flat and unprofitable

Seem to me all the uses of this world!

Fie on't! ah, fie! 'tis an unweeded garden

That grows to seed; things rank and gross in nature

Possess it merely.

The rest of the soliloquy is a rant against his mother, Queen Gertrude.

So, although there are metaphors, comparisons, there is no single, controlling metaphor or conceit.