Hi! Yes, the title screen track is called shadows, and a production company called Music2Hues composed and recorded the song. I thought this particular track was really well done and I bought the rights to use it for Skyland, thinking it would fit the title screen nicely. Unfortunately, Music2Hues has since gone out of business, and I don't know where you can still buy the song. However:
You could use the copy of the music track included in the game. You would just need to convert it to something that your computer can play, as the music data for the gba game is encoded in 16kHz PCM samples. You can fetch the raw data file here: https://github.com/evanbowman/skyland-beta/blob/master/scripts/data/music/shadows.raw (click the download button or "view raw")
Next, open the file as raw 8-bit signed 16kHz PCM samples, and export it to mp3 or something. In the free Audacity music editor for example, File->Import->RawData (Encoding: Signed 8-bit PCM, 1 Channel Mono, Sample rate 16000)