Brighter colors generally help with a cheerier tone, but you should try adding some perspective. The road makes me thing that everything is facing top down, but the house looks like you're looking at it straight on from a standing position. The house needs to be a bit more 3D, otherwise it looks like a sticker on a board.
The character could also use a bit more contrast. He looks good, but there's a lot of colors that either don't need to be there, or need to be differentiated a bit more.