Really enjoyed this. It's one of those games that fits together extremely well - the music, the simple sprites, the snippets of text - and the difficulty is extremely finely balanced. I found that "Gaia" rewarded my natural inclination to conserve resources, but still required investing a whole lot in beacons and time-slowing at a strategic point.
There's not all that much I can offer in terms of suggestions to improve it. Obviously another world and/or more puzzles would be fantastic, but that's just extra stuff. The only other things are down to convenience: I feel as though the foreman upgrade should probably come as standard (since the resource cost is trivial and it saves a ton of clicking, it's basically a must-buy anyway), and it would be good to see some kind of pathfinding ("Desert" in particular wouldn't work without that long trek through nowhere, but does involve a lot of mindless click-click-clicking). Those are extremely minor quibbles, though - it's an excellent game!