I'm happy to help from a mixing perspective, albeit not from a sound design/composition perspective.
From the off, I can see that EQ needs a little bit of work. The Piano sample you've got there has a beautiful, rich sound, but that doesn't always play to the advantage of an electronic dance producer at all - I'd suggest taking down some of those low frequencies (around 1-2 dB) around 300 Hz with a shallow Q to keep the Piano still sound natural. That'll make the Piano less bass-y and easier on the ears at first. Make the reverb less bass-intensive - Raise the low-end cutoff to about 500 Hz.
Likewise, the reverse crash you did at 0:09 needs a slight 3-4 Db cut to make it less sharp. The same crash at 0:22 (I like what you did that, changing the pitch, by the way) needs to be cut similarly.
The drums post-0:22 seem to be slightly clicky and overcompressed, but I don't know a lot about Drum and Bass drums. All I can tell you is to ease up on the compression a bit, and instead distort the drums ever so slightly, and EQ the high bass and the mids to get the punch without making the drums sound clicky.
The snare needs a tiny bit (0.5-1 dB) taken off of its high mids and highs (4-10 Khz area) to make it slightly easier on the ears, and the damp on the reverb needs to be taken down 5-or-so percent to make the sound slightly less fresh - This'll make it coherent with the bass-y piano. If you may have used a light compression on the snare, then don't. Take it off.
The crash at 0:31 needs to be longer, considering using a reverb with a high decay to lengthen that tail end, but be careful to not make it too damp, otherwise the reverb will be really sharp.
The sub needs to be centered; it sounds very sterio to me.
On 1:32, you need to be careful to automate the Q (resonance) on the low pass filter - If you want a good resonant filter, use a high Q for lower bassier bits to emphasise the bass, but when the low pass is very high (any high resonance above 5 Khz is a no-no) all the resonance does is bring out those loud, annoying, if not painful frequencies. Automate the Q so it's low to start off with (since the low pass is going from high to low, and you want a low Q so it doesn't emphasize the high sounds) and build it up slowly to about 10-20% as it gets to the bass (so then you bring out those rich, bass tones like you have at 1:34-1:35).
I'd talk about the rest, but I'm not in a pedantic mood.
