I agree totally with what [Only registered and activated users can see links. Click here to register]
said..your mate could be right about just the base line..that is, depending on how this piece ended up being used. If it was the background to, say, the credits..or something that plays in the background while a menu is showing, then that's fine I guess..it could do the job. But as an Ambient track it kinda falls over a little, in that it's halfway between something like what Brian Eno would do and a more up-tempo chill-out track. As it stands it's basically neither.
The thing is when you have a lead line like that, the listener's brain is automatically primed to expect other elements to come in, like high hats or shakers..followed by maybe a counter melody to balance the lead out a bit..but that doesn't happen here and the end result is you're left wanting more but don't get it.
The bassline is solid..I really like it, though you might want to cut the lows a little, so it doesn't smoother the lead and bring up the volume on it a tad in the mix.
The opposite applied to the lead. If this were mine, I'd take the volume down a bit, so it doesn't stand out as much as it does. You can still keep it up front, obviously..you don't want everything to blend into one musical mess..but as it stands, it kinda obscures the bass a little. I'd also cut the low end on the lead a little, too, as you have some pretty subtle modulation going on there and it tends to get a lost a little. While you're at it, add a touch..only a little, of reverb to the lead, to help give it depth of field..it sounds a little too up in your face right now. Plus reverb would help give it a more dreamlike feel and help draw attention to the modulation in a more artistic way.
Also think about adding a couple of little "sweeteners" to the mix..elements that will add more movement to the mix..like chimes or or something, whatever takes your fancy...and add a touch of panning, alternate each.
I know all of the above reads like a lot needs to be done, but it's not that much really..and, obviously, take all of what I've said with a big pinch of salt, as it's all based on what I would do personally if this piece were mine.
All in all, I like the vibe of this, but I would take it further, as it sounds to my ears like it's crying out to be developed more. Nice work, though.
Thanks for sharing.