Hi @Henry Ng Tsz Kiu!
It's a cute little piece but not without its complexities! Like, for example, the first musical statement is a double period with elision that leads into your second C minor tonal area. Although because of your heavy emphasis on G, I don't really feel like you ever really arrive in C minor and you quickly return to the G major theme. When you return to the main theme the phrase structure stays the same, but you vary up the modality of the 2nd theme, opting to stay in G major instead of C minor or G minor. The final statement of the A theme you marked scherzando which is appropriate because it's the third time that the listener is exposed to the material and hence starts to expect the piece to conclude soon. So going faster gives a sense of excitement, exhilaration and rushing towards the end which makes the end sound that much more conclusive when it comes. Great job and thanks for sharing! It's not surprising that this piece is doing well in terms of views on YouTube, since it is quite accessible and fun!