I can see a minor space program as a technology to going to an destroying the meteor - be a fun alternative to the lasers and would stay with the premise of the game. The idea of terreforming worlds is a whole different game. Firs of all tehre is a great leap between the reality of Eco and the utter Sci-fi fantasy of terreforming a planet.
There is no way to start out on 'Mars' and terreform it. Even if you do very little research on terreforming Mars you quickly find out that without more Mass, and a greatly enlarge the magnetosphere no amount of work done of the surface of Mars will terreform it. In its current stat you could bring oceans of water and it would all out gas immediately. mars would need more mass - brought by force collisions from other bodies (and then 1000's of years wait for the planet to stableize), it would need its core rotation speed up - NASA has put forward some plans about digging into the mantle and setting of explosions that would do this. The other way is to coax some large bodies of other bodies into orbit around Mars at Lagrange points to use tehir magnetic field to shield Mars and hold water in and allow it to develop an atmosphere. And taht is just teh very early start of terreforming a planet. Terreforming a planet is still very much science fiction and really has little to do with ecology until a planet is well into a terraforming phase and supporting life. Since most of what we would have to do to terreform a planet would need to be done from space - without technology we don't have except in fictional books, would have to be done from space most likely from generational ships big enough to go coax other bodies to Mars you are talking about a space exploration and terreforing game, not an ecology game.
There is a huge leap from putting a guy in a rocket , in a space suit and sending him to a meteor to blow it up - and while that is still science fiction at this time for us - we do have the technology to do it and have landed unmanned probes on asteroids so the do-ability of the concept is there. So even though do it would fall under science fiction, I could see the stretch to doing as the byproducts of getting a man and a bomb to the meteor would be another polluting factor you would have to work against.
Terreforming another planet, while totally science fiction and not based on any technology we currently have does not really have anything to do with ecology and community building etc. Nothing that Eco is really about. Terreforming a planet, even if you found one with the right mass and a magnetosphere, would take generations unlike what you see in the movies. Much of that time would be spent living aboard a ship orbiting the planet and when you could move to the surface it would still mostly be in sealed bunkers. To terreform even the most cooperative planet would be a generational project and it would not be about ecology and community building and working toward saving a planet; but about team choosing and leadership, scientific experimentation and space exploration and developing a new world - a totally different premise. Great premise for a different game but very different from the game Eco and the systems in use in the game.