What are some different kinds of music Mozart wrote?

Piano Sonatas, Symphonies, Serenades, Opera, Arias, etc.

Mozart wrote pretty much all the different types of music of his period. Symphonies, concertos, sonatas (for each of the contemporary instruments), chamber music (trios, quartets, etc.), serenades, fantasias, concert rondos, etc.

Wolfgang Amadeus Mozart was a prolific composer. Basically, he wrote in all the genres in his period, except ballet.
He has about 700 works, which covers a large palette of musical domains.

Orchestral works: symphonies, serenades, divertimenti, sonatas (he has few "sonate da chiesa", written for orgue and string orchestra);

Vocal works: operas, liturgical works (18 masses, a Requiem, different type of works which are used in the liturgical procession as Offertory, Communion, choral works a-cappella), concert arias for voice with accompaniament of small orchestra;

Chamber music: duets (mostly for violin and viola, but for 2 french horns too), trios (for strings, for winds, for strings and winds, Trio for clarinet, viola and piano etc), quartets (23 string quartets, and quartets for winds and strings - Quartet for oboe, violin, viola and cello, Quartets for flute, violin, viola and cello, 3 quartets for piano, violin, viola and cello), quintets (6 string quintets, for 2 violins, 2 violas and cello, quintets for winds and strings - the famous and splendid Quintet for clarinet, 2 violins, viola and cello, the also famous and beautiful Quintet for piano, oboe, clarinet, french horn and bassoon, Quintet for french horn, violin, 2 violas and cello); also, in the chamber music section are included the piano sonatas, the few 2 pianos sonatas, the sonatas written for piano and violin, the few sonatas for flute and harpsichord written in his youth, in Italy, the bizarre sonata for cello and bassoon (I mean "bizarre" in the instrumental combination); Mozart has also a few fantasies for piano, for orgue; variations (mostly for piano); Menuets, German Dances, Contradances, for piano, for chamber ensembles, for small orchestra;

Concertos: mostly for piano and orchestra (27, as I remember, and few for two pianos and orchestra, and even for three pianos and orchestra), 5 (others says 7) concertos for violin and orchestra, beautiful concertos for winds and orchestra: two concertos for flute (the second, in D major, beign a transcription of the oboe concerto; they are played both of them), an Andante (KV 315) for flute and orchestra, which complete the KV 313 (first concerto) and KV 314 (second concerto); four concertos for horn and orchestra (plus a Rondo for horn and orchestra); two bassoon concertos (today, the KV 191 is played more often), the splendid clarinet concerto KV 622 (orriginaly written for basset horn); a double concerto for flute, harp and orchestra; a Simfonia concertante for violin, viola and orchestra (is worth to mention that the solo viola is tuned a half tone higher - scordatura - so the viola part is in D major, while the other instruments are in Eb major); a Simfonia concertante for oboe, clarinet, horn, bassoon and orchestra.
Mozart has also a few songs (in german "Lied") for voice and piano, for choir, for choir and piano.

If I missed something, I'm sorry :)