Good song man. It has a nice vibe to it, good sounds and overall good mixing makes this song quite enjoyable. But I do have some critique for you as well.
Because of the songs simplicity (meaning that each rhythm in the song is not that complex) it tends to get repetitive. Adding rap/vocals to the song could very well nullify this and make the song sound so much greater. But to effectively add vocals to a song is quite a feat, so I'll wish you the best of luck if this is the direction you are taking this song. Overall good work, ill be checking back later to see what you've done.
Check out my stuff if you have the time