The strings could be better, yes. I think part of the issue is the same string attack, sustain and vibrato/expression across much of the piece. So the strings just sorta sit there and I think that's partly why you feel like they're not working as well. 

I would try and automate volume and if the samples have any round robin or expression/modulation changes built it - work with those as well. The other thing is you could try and embrace the more static writing in the strings by doubling with some nice, mellow synth pads. Or you could also try and change some of the string writing itself. I could see some nice string arpeggios working nicely and giving a section of the piece more development. Or perhaps some kind of ostinato/rhythmic figure. Or at 1:09 the strings could change to tremelo with some swells built into the chord changes. 

Edit: One more suggestion: You could double the strings with some mellow french horns to give the sound more warmth. If I were you, I'd only do this at certain moments because, like I said before, if the arrangement is too static then the effect is lost. 

Finally, a word of encouragement: game music doesn't have to sound real. It just has to make a connection with the player and the game! Overall, however, I love the piece! Nicely done!!