Eufloria

Eufloria is a Real Time Strategy game by indie developers Alex May, Rudolf Kremers and Brian Grainger. Inspired by the Dyson Tree hypotheses, the player assumes the role of Plant Aliens who seek to colonize asteroids in order to hasten the return of the Growers. Using ten seedlings, the player can build either a Dyson Tree, which produces more seedlings, or a Defensive Tree, which releases flying explosive fruit.

Over the course of the game, the player encounters the Greys, who are seedlings driven insane by The Virus, and later the creators of the virus, who are themselves another seedling empire.

Described as a simple but charming game... And very addictive.

Tropes used in Eufloria include:

Action Bomb: Mines. However, their four laser beams are so effective that they straddle the line between this being the main purpose and it being just a Taking You with Me.
All Your Base Are Belong to Us: The game is a never-ending series of these between your enemy and you.
Armor Is Useless: While Defensive Trees do have their uses and value, the core of this game is about attacking new planets, rather than defending old ones.
Beam Spam: How seedlings fight. Mines have four continuous beams that can easily decimate a low-energy seedling army.
Color-Coded Armies: played with. You can choose one of the available palettes for your forces. Enemies have their palettes randomly chosen from the same set you do (with the exception of the Greys, who are always, well, grey), which means that occasionally both sides look exactly the same, distinguished only by the unique faction symbol.
Design Student's Orgasm
Dronejam: No matter how many seedlings you have clustered around that asteroid, or how many trees you have blown up, they'll still only enter one hole one at a time. If a Defensive Tree is still active, this can be a serious problem, as most seedlings cluster around the entrance.
Fog of War: Until you send a seedling to an asteroid, all of its properties are unknown. Afterwards, you can see it forever, even if you lose all the neighboring asteroids.
Have You Seen My God?: The Mother Tree worships the Growers, and the seedlings' main motivation is to hasten their return by colonizing asteroids.
Neglectful Precursors
One-Hit Kill: Every seedling can do this in 'Solar Flare'.
Petal Power
Plant Aliens
Power Glows: Super seedlings.
Precursors: The Growers.
Scenery Porn: The 'dark' levels are especially gorgeous, even though the art style is simple.
Suspicious Videogame Generosity: The first level of the last chapter, 'Event Horizon', opens with "Our enemy is weak... They are retreating from our might! Round them up and finish them off." A few asteroids ahead is a large asteroid with very good stats. As soon as you take it, the enemy attacks with a large force of super seedlings.
Taking You with Me: Mines, besides their four laser beams, explode upon death. This means that the usual method of removing them can end in disaster.
Too Fast to Stop: 'Speed' type seedlings generally avoid the aforementioned Dronejam problem due to attempting to hit the entrance, being denied due to another seedling being closer, bouncing off and flying into space to make another pass.
Unwinnable: Related to Zerg Rush below, it's common to run into situations where an enemy empire has enough seedlings to lock down one of their asteroids, and send an equally-sized fleet to your nearest planet. Each fleet will be more than enough to do their job, and will number more than your entire asteroid seed population. Because levels are somewhat randomized, it's (usually) a matter of restarting.
The Virus: What the Greys are afflicted by. It's actually a biological weapon created by one of the other seedling empires.
When Trees Attack: Defensive Trees.
Wise Tree
Zerg Rush: A long enough game will almost certainly devolve into this, as the only effective counter is another Zerg Rush.