It didn't sound too 'suspenseful' to me. I think you'll need to play about with it to get that feel, if that's what you're looking for. Trust your ears on that one. If you're going to end with the string on it's own, at least strip down parts of the track before you have that string on it's own or fade out the sounds. It sounded abrupt since you went from having multiple tracks playing to just the strings very suddenly, so try to rectify that! By saying you want to have it lead into 'Hydrocity' I presume you mean you want to continue the track into another? Would this be in one track as a medley? If so, be careful regarding OCR's submissions standards. Taken from the Submissions standards and submissions page on this website; Keep that in mind if that's what your going for. Check out medleys other people on OCR have done to have an idea of what is acceptable. If you mean that your going to do a separate ReMix for the Hydrocity level but have the two tracks merge into each other (like they're on an album), then I'd strongly advise you not to do that (at least not on OCR). The tracks you make should be like a radio edit, with a coherent introduction and ending (this is why I had a problem with the start and finish of your track). It makes sense for a single track on it's own to have closure and not end on a cliffhanger of sorts. It works in HBO TV series', but not in music I'm 'fraid I presume restructuring the track would count as adding original arrangement, but I mostly meant something along the lines of 'different feel'. Essentially, I believe it's a case of taking artistic license on the original midi of the track, such as changing parts (EDIT: Changing parts is a bit too vague, I mean using original drum beats, bass rhythms ect.), adding counter-melodies and putting in instrumental solo's. It's like putting your own personal stamp on the song. What you need to do in order to make the track original is hard to nail down, and I'm not 100% sure on what is needed to strike the sweet balance between the track not being a cover and not being unrecognisable. Again, I'm going take the cheap way out and suggest looking at posted OCR tracks to see how similar/different they are to the original source. It is seriously the best way to find what OCR is looking for. I hope I'm of some help here!