This is a enjoyable and iight-hearted sonatina for me which fits well for a sonatina. I really enjoy it!
To begin the recapitulation from the subdominant G major, then to modulate back to D major (overall tonic, G major's dominant) as in the exposition is very Mozartian for me like in his "Easy" piano sonata in C major (which is not easy at all!!!). When I say it's Mozartian I didn't look at your reply but later find this!
The modal mixture in the second subject, vivacious rhythm and lighter texture remind me of Mozart as well!
Sonatina needs not be easy to play though, like Ravel's or Bartok's sonatine. The triplets against semiquavers are definitely not easy for novice and could be challenging for intermediate players as well, but it creates good contrast to predominant steady texture!
The last half of b.7 and similar is quite neo-classical for me with harmonic emphasis on the mediant minor chord.
For a sonatina the length is absolutely fine. In the last movement of Beethoven's op. 10 no.1, the development only contains 11 bars, and the tempo is pretissimo so you can imagine it flows within a few seconds:
Also there's a type 1 sonata named by Hepokoski in which there's no development: The recapitualtion immediately follows the exposition after the cadence in the second subject. It happens more in the slow movement like that of also in Bee's op.10 no.1, but for a sonatina it's fine to have a diminutive development or no development at all.
I love playing the Clementi and Kuhlau piano sonatinas! They are very lovely!!
Thanks for sharing Peter!
Henry