I will state that I have also lost from suicide. We were never best buddies, but he was 18 ( a senior ) when I was 14 and a freshman in high school. No note, no warning, just a Facebook status with lyrics from Sad Statues by System of A Down (You and me will all go down in history with a sad statue of liberty and a generation that didn't agree).
I believe a topic like this should be handled with *extreme* care. I am for the topic being expressed. I have always found that negative emotions have the most impact. As a musician I tend to write sad, minor key things because they have more of an impact a large portion of the time.
I think you need to focus on believable settings, individuals (having the entire race depressed would get old and desensitizing fast... imagine a planet full of the robot from Hitchhiker's Guide to the Galaxy), and consequences. Perhaps you can go through your life making changes and juggling your mental health... if and when a character commits suicide, do a review of consequences, how it affects the other people, the lost opportunities, the pain, etc.
Do not glorify it.
I am going to suggest (at your discretion) reading Johnny the Homicidal Maniac... I very much liked the way suicide was handled in that. It was very dark. I thought perhaps it could send the wrong message to people. But as much as it is completely ridiculous, there were a lot of in depth moral monologues on the topic. The main character tries to commit suicide many times and inevitably fails for different reasons before accidentally being killed by his contraption after deciding he wants to live... that is not the end as there is a lot of satire as he floats between heaven and hell before neither wants him and he is kicked back to being alive. So, not an entirely good analogue ;)
Your second game reminds me on Planescape:Torment in places, i would definetly go with the slightly modified version of the second game. If you can make your game distubing just enogh to send chills to the spine, as in psychological horror, your game might turn out amazing.