Firstly, it adds more options for sim cell phone usage and applies to not just playable sims but NPC sims as well. The Slice of Life mod is one of the most infamous inclusions in the community due to its ability to adds tons of realism to your base game. Seeing your sims watching and playing things you do in real life as well is sure to make their world feel a little more real to you as a player.
The first pack only features Nintendo games including Super Smash Bros.
These mods requires City Living to function, and your sim will have to max out their gaming skill level in order to see all the possible options. It will add more depth to your sims and make it a lot more satisfying when you keep them content. It essentially makes the moods of your sims a lot more complex, instead of Happy just being the norm with not a lot of variety in how they achieve that happiness. The roles of Happy and Fine states are changed, Happy is now a full positive mood and Fine is a boosting mood for other states.