hmmm
they all sound a bit samsy, but if you want to keep that kind of style, then i suggest taking one of the songs and liven it up a bit, like something from the game Red Alert 2, the songs in that game was all action and alive, this loop is the perfect relaxing, constructing, researching song, probably the second song could be the liven up song, something to immerse the player into the game, this is suggestion of course, not something to really, follow but you never know, it could work :)
Incidentally, I was gonna add an ambient "marching" track to the game, just like Red Alert <3 I've owned the soundtrack to that game for years, it's inspirational.
And you called it - this track is the "break" from the higher energy songs. I have a minor chord one, a creepy one, and this is the "nice" one I suppose. It's all major chords and in a different key than the other two. All I need now is an ambient song with more sound effects than music.
cool
I love the dark ambience that it creates just like the rest of the mastermind soundtrack.