In case you only have a few minutes maybe I'll "excerpt" a few of his comments (assume everything below in double quotes):
Sonata 1 Op. 2, No. 1
Sonata 2 Op. 2, No. 2
Sonata 3 Op. 2, No. 3
...there is already an "in your face" attitude toward convention in B's approach--...(he) delights in disappointing expectations and throwing syncopations and harmonic raspberries at an unsuspecting listener. He also indulges in his adored practice of tampering with the scansion ("meter rhythm") to produce uneven phrases and measure groups.
Sonata 4 Op. 7
...perhaps the richest and most striking of all of Beethoven's early piano sonatas..
Sonata 5 Op. 10, No. 1
...B. launches the work with a bold, rising figure outlining the C minor triad, which is followed by one of those characteristic gentle answers so often found in his first subjects. The movement is full of breathless agitation.
Sonata 6 Op. 10, No. 2
...a short work with a good deal of humor and a few touches of suppressed anger.
Sonata 7 Op. 10, No. 3
The power of the whole opening is such that one may well imagine this movement coming more as a shock than a revelation to B's hearers; what it reveals to us today is Beethoven writing as Beethoven, perhaps for the first time in his piano sonatas. The centerpiece of the sonata is its slow movement, marked Largo e mesto. It is a movement of enormous grandeur and feeling for 1798, openly tragic in character, pathetic in its declamation, and wrenching in its passion.
Sonata 8 Op. 13
Beethoven's writing in the Pathétique is striking from the outset. (I don't need to sell this one too much I think...)
Sonata 9 Op. 14, No. 1
...a work in which, to quote Eric Blom, Beethoven "turns every pianistic device to an expressive purpose."
Sonata 10 Op. 14, No. 2
...one of B.'s most relaxed sonatas, a slender work in a key that tended, for B., to evoke music of lightness and grace.
Sonata 11 Op. 22
..a nod to convention..
Sonata 12 Op. 26
...extraordinary command of variation technique. A scherzo follows, setting the stage for the sonata's most dramatic movement, a striking essay in A flat minor subtitled "Funeral March on the death of a Hero." Foreshadowings of the "marcia funebre" from the Eroica Symphony lurk within...
Sonata 13 Op. 27 No. 1
The sonata opens with a "fantasy" movement that has a simple, three-part outline..B. fancifully contrasts the opening and closing sections--based on gently repeated chords--with a breathless middle section that is all gruffly accented chords and flying sixteenth notes.
Sonata 14 Op. 27 No. 2 (Moonlight)
The famously repeated three-note figure here, most likely inspired by the Act I trio of Mozart's Don Giovanni (another "fantastic" nocturnal scene), becomes a fatalistic middle-voice ostinato under the movement's real melody, a tolling subject of truly desolate character... The concluding Allegretto and Presto movements present the sonata's true argument, and are a musical Scylla and Charybdis full of challenges to the performer's skill.
Sonata 15 Op. 28
...foreshadows Beethoven's middle-period manner in its breadth and scope. It is a work of exquisite craftsmanship throughout and, for the most part, poetic content, particularly in the opening Allegro. This relaxed movement, whose amiable first subject is set over a drone, does, however, have a turbulent development section that stays mainly in the minor mode.
Sonata 16 Op. 31 No. 1
The (3rd M) finale is a light-hearted rondo in which the pot is always kept at a boil thanks to the near-continuous cascade of sixteenth notes. There is a wonderful, "you'll never guess where the end comes" coda that caps the humor of this extraordinary "ordinary" sonata.
Sonata 17 Op. 31 No. 2 (Tempest)
The Allegretto finale, also in sonata form, is a gentle country dance of virtually unbroken sixteenth notes, with accents placed in such a way that any rhythmic monotony is avoided. The mood is sad, even somber, with a hint of wistfulness.
Sonata 18 Op. 31 No. 3 (The Hunt)
The scherzo, in 2/4 time rather than the usual 3/4, has a restless quality, enhanced by constantly shifting accents and cross-rhythms as well as some remarkable harmonic manipulations. B.'s gift for melodic invention shows in the theme of the minuet, and there is a subtle play upon expectations throughout the movement.
Sonata 19 Op. 49 No. 1
Sonata 20 Op. 49 No. 2
...composed between 1795 and 1798, and given to a publisher years later, without B.'s consent, - Both carry the designation Leichte Sonate--"Easy Sonata"--which does not mean that they are inferior in any way, just relatively easy to play.
Sonata 21 Op. 53 (Waldstein)
...comes as close to formal perfection and total mastery of materials as any in B.'s canon, and its brilliance, harmonic daring, and sheer energy make it a shining example of the middle-period style
Sonata 22 Op. 54
The finale is remarkable for the fact that, almost throughout, it is written in two single parts, like a Bach invention. The resultant counterpoint, while scarcely going "by the book," produces an alluring play of harmony and texture.
Sonata 23 Op. 57 (Appassionata)
...sinister opening subject that issues sotto voce from the depths of the keyboard. In the opening Allegro there are precipitous changes of mood--from somber, to elegiac, to darkly furious--which listeners will recognize as typical of Beethoven's minor-key expressiveness. Indeed, the accents and contrasts here are so intense that the piano itself sometimes seems to cringe from the task before it.
Sonata 24 Op. 78 (Fur Teresa)
...extremely concise and economical, the dominant affect one of ecstasy untroubled (except by occasional touches of the minor mode) and songful, skipping delight.
Sonata 25 Op. 79
The sonata's Andante is a gentle siciliana, and it unfolds with all the ingenuousness of a short, simple song.
Sonata 26 Op. 81a (Les Adieux)
Grounded in B.'s noble and heroic key of E flat, what follows is music of extraordinary power and imagination dealing with the emotions of separation and reunion--music meant to be listened to with the eyes and heart as well as the ears.
Sonata 27 Op. 90
B. good-naturedly told the sonata's dedicatee, who was about to remarry, that the first movement represented "a struggle between the head and the heart," while the second was "a conversation with the beloved."
Sonata 28 Op. 101
The opening movement, comes prefaced by the marking "mit der innigsten Empfindung" ("with the deepest feeling"). There is a very different character to the ensuing scherzo, which is cast as a quick march: it is brash, forceful, assertive, with sharp dissonances and a tendency toward violence that stands in marked contrast both to the opening movement and this movement's own rather courtly middle section.
Sonata 29 Op. 106 (Hammerklavier)
...some of B.'s most powerful, assertive music. Its exultant opening bars, in which fistfuls of notes are literally hurled at the keyboard, contain the chordal building blocks out of which the entire composition is constructed.... (Re: the Adagio) up to this point in the sonata, Beethoven-the-thunderer has done most of the talking; here, it is "the still, small voice" that is heard...The finale...sets the table for a three-voice fugue so elaborate and eventful it seems more like a fantasy in which long arcs of invention are sustained by brilliant imitative writing.
Sonata 30 Op. 109
...the first movement of Opus 109--in which sections marked Vivace and Adagio alternate with one another according to a freely adapted, fantasia-like version of sonata form--is actually more Hegelian than Darwinian. Within its dialectic of contrast there is remarkable tension, which allows B. a particularly wide range of expression.
Sonata 31 Op. 110
(Re: Finale) ...A series of modulations leading back to A flat prepares the movement's extraordinary conclusion, a hymnlike passage in which B., approaching something like ecstasy, almost runs out of keys at the top end of the piano.
Sonata 32 Op. 111
Its two movements contain some of the most compelling and engrossing music ever penned, and represent perhaps the single most perfect crystallization of B.'s late style outside the final quartets.
Whew! 1,340 words. So much for a short read. I highly recommend the unabridged essay - it's superb.
A couple other "Complete Piano Sonata Overview" resources:
Noriaki Nomoto's Page on the 32 Sonatas.
Andras Schiff's Lectures on the 32 Sonatas (mp3 lectures).
Tomorrow I'll feature a different way of looking at Beethoven's 32 sonatas which will only take 2 minutes and 32 seconds...