"thank you for trying this demo"
That's probably because you haven't bought Sylenth1?

- Did you use stock FL drum samples? You shouldn't use 'em...even if you want to, process the crap out of 'em.
- That wobble could use some processing/effects as well.
- At around 1:44, the volume gets really loud for some reason.
- 2:06, the melody for the keys are somewhat dissonant.