The sample's good, but it needs some variety when it's sequenced. Quick rolls (like the one at 0:04) don't sound all that convincing when you're using just one static sample; it's got sort of an Aphex Twin thing going on- a stuttering sound- which I imagine you don't want. Perhaps make a few different copies of the sample, pitch shift some up a bit and some down a bit (just a few cents max), and use a gentle low-pass filter on certain ones. The hard hits can have no filtering, but the softer you want the hit to sound, the more highs you should roll off. Nothing crazy, just enough to add some darkness to the "softer" hits. The key is to not have two consecutive hits be exactly the same, and varying pitch and filter frequency is a good way to get this effect if you're only using one sample.
If you're using NI's Battery, there's a modulation matrix where you can assign any midi data to affect any of the parameters. For instance, you can assign "Velocity" to affect the cutoff and/or resonance of a low-pass filter, thus automatically making hits with lower velocities sound softer/darker. You can also set Velocity to affect pitch; harder hits will be slightly higher tuned. Or you could use an LFO to modulate pitch so that each sample will be tuned ever-so-slightly different, making them sound like different hits. There's all sorts of stuff you can do here, and all with just one sample (a lot of samplers have some sort of mod matrix, but I'm just using Battery as an example because it's the one I know inside and out). If you keep it subtle, it can sound pretty convincing. Good luck, let us know how you progress!