The computer game Minecraft does not appear to contain the overt sexual and occult themes of other games. Known as a "sandbox" game, some have described it as "digital Leggos." Players can make whatever they want of the game by using blocks to build all kinds of structures such as houses, works of art, etc., and then defending these buildings from spiders, zombies and other bad-guys that try to tear it apart at night.
Most of the warnings I've seen are about what can happen if a child goes beyond the single player game format and opts to play online with other players. This can introduce all kinds of personalities into your child's play, including adults who are unknown to them. Parents have suggested that if their child does play online, they should monitor his or her game activity and consider getting a private "family" server (costs about $6 per month) upon which your child and known friends can play.
As for wholesome computer games and how to find them, you might want to check out an excellent library of reviews of today's most popular video games at a site called Plugged In. Best gaming monitor award for 2017. It's hosted by the Christian apostolate, Focus on the Family. You can scan the reviews and pick out good games as well as read which ones to avoid.
Focus on the Family also offers a free multi-session "course" on video gaming for parents to help them understand types of video games, how to choose games wisely, how to spot if your child is becoming addicted to video games and what kind of safeguards to put in place for video gaming in your home.