This is a somewhat unusual piece that sounds more difficult than it is. Although it can be challenging at times, it's also fairly short with repetitive sections.
Difficulty = Moderate
The Bach inventions are an important part of any aspiring pianist's repertoire. Despite being very technical, this invention is among the most accessible of all inventions.
Difficulty = Somewhat Challenging
Beethoven's Sonata No. 20 (Op. 49 No. 2) is widely considered to be the best choice for any pianist's first sonata. Compared to typical sonatinas, this sonata is generally longer and more technical. However, it's also the most accessible among all Beethoven sonatas.
Difficulty = Challenging
The posthumously published "Waltz in A Minor" is widely considered to the be preferred entry into the Chopin waltzes by many teachers. Outside of one specific difficult run, this piece is very accessible and rewards practice time very well.
Difficulty = Moderate