1. It doesn't mention exactly which games are there, the info there is very sparse and confusing and seems to be focused around some weekday time based hackathon
2. How exactly are those "engineering simulation games"?
The car and flight sims are engineering simulations - differential equation solvers employing multiple degrees of freedom, flight models and tire models validated vs. data, etc. Game manuals, which are hundreds of pages long, describe how to, e.g., set your differential coast and power ramp angles to tune racecar responsiveness, and how to decide whether a one-circle or two-circle dogfight is more advantageous based on the specific power diagrams of your aircraft and your AI opponent's. These games have staying power because they are clearly labors of love, where accurate physics was top priority in game development. Dave Kaemmer, a top sim racing developer, summed it up this way: "We don’t care if it’s fun or not. We care if it’s real"
There's a python script that makes the organization more clear. Once you've installed the games package, run "./launcher.py" at the ubuntu command line to see a text menu "Top Level Menu" which launches the games.