Good effort
Does not even sound like this was made in Mario Paint so what did you use instead? The tone of the song seems very light and playful here as the beat marches on and keeps going. Kind of sounds like something I would hear in a humorous and light RPG game.
The bass trombone sounds really nice here and I like the flow of that beat. Then there is the drum beat which feels like someone banging on plastic in a very good rhythm. The violin here is quite nice to hear too. The other instrument is pleasant on the ears so great work there. Not much to improve here aside from maybe making it longer.
Overall, good little short piece, very light feeling.