When a seed meteors into the ground, it finds itself in hostile terrain. Nasty-looking plants sit nearby, easy to provoke by the slightest bit of resource gathering. Given that it appears our plant is the alien invader, one could suppose the evil plants were just defending their turf. To beat them all and advance, the plant has to grow to full maturity. It gets this done with local resources, gathered across the level. There are three types: slurpers draw resources from underground reservoirs, catchers get resources from falling fluids and breezers snatch the air. Each of these, however, agitate the local plants, who in turn retaliate with pollen.
In step your trusty robot chopper things, the so-called defenders. Also in three flavors, they deploy shields that stop the pollen. Take enough hits and they lose a shield, damage that you can repair and an ability enhanced by upgrading the unit. The resource gatherers can also be upgraded and repaired, but they (and your plant) need the protection of the defenders. Defenders can be placed anywhere, but the resource gatherers have specific areas where they fit. Click the right mouse button brings up a radial menu from which you can build.
With each level you can asses the threat by choosing another option on the menu, bringing up a risk assessment of the map. It shows how likely certain plants are to attack and where the resources are located. During the game the view is cropped more closely, but you can zoom out. Money is earned via the resources, so the trick is to gather enough so that the war coffer is kept topped up and the defenders have shields.
Analysis: Technically this is an educational game, teaching about the need for resource balancing. That much is obvious with the three resources, which essentially represent fossil fuels, hydro power and air power. In reverse order is the magnitude of payout: oil gives far more than air. But to balance that it also agitates the plants a lot more and depletes quickly. It is easier to go for air, slow yet unlimited, and not upset the natives, but in later levels the assaults become relentless and you have to swoop around, grabbing resources smartly and quickly.
It's an interesting formula that draws similarities with the resource management theme it represents and certainly makes for one of the better edu-games around. That's because it hardly has much to teach, but makes for an intensely fun tower defense game. A Facebook link-in also means that you could plug your account in and compete on the leaderboards. Finally, there's no closing this off without mentioning the nice graphics. It's a game made with a budget, and it shows.
If one criticism comes up, its that you will go through at least two thirds of the game before you are forced to play smartly. Obviously the challenge is heightened if you want to compete on score, but even at a laid-back pace it makes for a fun bit of gaming.