I am very bad at creating "best of" list due to all the games I've played; I always have trouble narrowing down my list. With that said there are few games that always find their way to the top, such as X-Com. Star Control 2 is the only reason why I still have a 3dO hooked up in my living room and is one of the best games I've played.
Long before Grand Theft Auto teased gamers with the idea of exploring an open world, Star Control 2 gave us the entire universe. The story is that a big intergalactic war took place between a good group of alien races and the bad guys. Earth decided to side with the good guys but unfortunately they lost, reducing the races into slaves for the bad guys. The player is part of a lost expedition who inhabited a mysterious world where they found the means to produce a starship. The game begins with the player arriving back in our Solar System to find the Earth encased in an anti escape field.
The overall objective of the game is to save the universe (or more specifically Earth) from the bad guys. To do that you'll have to explore the entire universe for resources, allies and new technology to give you a fighting chance. After a brief introduction you'll have the entire universe open with the only limitation is your fuel supply.
There were three main systems present in the game. First is controlling your flagship. Whenever you are in hyperspace or in a solar system you'll be controlling your ship. Your ship's speed and turning ability are based on turning jets and thrusters that you can outfit your ship with. When you're in hyperspace you can bring up a star map of the universe to determine your course. Each second moving in hyperspace uses up fuel and if you run out you'll be left stranded.
Near Earth is a space station that acts as your home base. This is where you can buy fuel and outfit your ship with new parts. In order to afford these upgrades you'll need resource units or RU which is where system two comes in.
As you explore you'll come across planets where you can send a lander down to the surface to search for minerals and alien life. Planets are varied with some more dangerous than others; of course the dangerous planets have the better minerals but you'll risk losing your lander. Planets that have alien life can be harvested for research that can be sold to an alien trader to get special technologies like better weapons.
The last system is the actual combat. Whenever you meet a hostile ship either in hyperspace or in a solar system you'll have to fight to survive. Combat is arcade style with the ships fighting on a 2d plane. Each species in the game has its own unique ship style, differing in terms of special attacks and stats. The # of crew members aboard dictate the health of the ship and once depleted the ship is destroyed. If you have multiple ships in your fleet, you will decide which one will fight first. At the start of the game your flagship will be very weak but through upgrades it can become very powerful. However if your flagship is destroyed it is game over.
Similar to X-Com your actions don't exist in a vacuum and there is a time limit to deal with. Eventually the two biggest alien races will have a war with one of them winning which leads to a mass genocide of the Universe. Once the Earth gets destroyed you will lose the game.
That last story theme is one of the problems (or flavors) of old school design. There is no quest log here and you'll have to be prepared to take notes or have a really good memory. When talking with alien races they may throw out the name of a star system for you to explore which leads to several minutes of scouring the star map looking for the elusive sector.
Trying to balance out saving everyone with getting your ship power up is one of the challenges of the game. During one of my plays my flagship became very powerful but in the process I took too long and one of the alien races was destroyed. The designers knew about this conundrum and made upgrades for your ship costly requiring the player to decide when to help the other races and when to explore.
What I find interesting is that there are several design similarities between Star Control 2 and X-Com. Both titles have unique game-play based on three different game systems. X-Com had base building, ship combat and turned base combat. Both titles also play with the concept of having to deal with time constraints. In X-Com you only had so long once an alien ship has been detected to get to it before it goes away. Also eventually Earth will have multiple alien bases and you will start to lose your funding.
One element that hurts Star Control 2's re-playability is that the universe is always set up the same way. After a few games you'll know where the quality systems are which cuts down on the exploration. While in X-Com battles and enemy attacks are always randomized.
Another area where both these games exist is that I have yet to actually beat either one. Joining them on this list would be Shin Megami Tensei: Nocturne as games that I want to finish at some point. For those interested in trying out Star Control 2 you have several options other than buying a 3DO.There is a freeware version of the game that has been out for several years which you can find here. Good Old Games just released a two pack of Star Control 1 and 2 available from their website.
There is a Star Control 3 out there but I have been advised by people to deny its existence and have no experience with that one.