Pretty good
Like Taennyn I ended up just focussing on colours, the only time I bothered looking at the numbers at all was while waiting for colours to finish changing. Maybe if the numbers were clearer it would be worth using them more, the stylised font looks good but is not very practical. Nice game though. Maybe have it gradually speed up if you redo it at all? And the Play Again button doesn't seem to work, but at least the Main menu one does ;)