I am working on a composition but it has barely this chords: C, C aug, Dm, G, G aug; and in very short parts: Em Fm and Am. And little variations. 
The composition is for piano, written in the key of C major, and I am worried that most of the composition is repeating the C and D chords with little variations. Is this wrong? Is this of bad taste? Is this monotone? 
What do you think of the harmony in this cases? 
Thank you for your help.