Not a parent but I still agree that short games are great, 2-3 hours are great (or even a bit less, there is a reason for the standard 90 minute movie). 4-5 hours can be nice too ("chapter" divisions are helpful). Games are inexpensive and plentiful these days so a nice short game is great for everyone not just people with little time for playing games. (I guess I should say the flip side is that time spent with characters is one of the interesting things that games can use to good effect and bonus objectives that encourage you to explore details of the world can be nice too depending on the type of game and are easily skipped).

The best game settings have a scene to illustrate the effect of choices along with estimated(?) performance. Unfortunately I haven't seen that too often (mostly Falcom games that PH3 worked on). I agree that stating the impact on performance is quite helpful when settings need to be lowered. Usually they are ordered "best performance" to "nicest looking" so I set the last one and only fiddle with them if necessary (a smooth 12fps works great for me so luckily that isn't often).