CD Projekt Red recently confirmed Cyberpunk 2077 will have street racing but now they completed the side activity roster with boxing matches. Furthermore, certain characters will apparently have advanced control of the Flathead robot.
CD Projekt Red saw potentially unexpected levels of success with GWENT in The Witcher 3, even prompting them to release a standalone TCG with the same name.
It appears they are looking to one-up this particular side activity's popularity with Cyberpunk 2077 which will have three distinct distractions from main and side missions - street racing, shooting range and boxing. The former two were revealed earlier by Lilayah while boxing was technically revealed in the E3 2018 trailer but never confirmed.
Some may find three side activities to not be that much but Cyberpunk 2077 will be filled with other minigames such as hacking which will allow players to access better functions the better they are with the skill.
On a somewhat related topic, players will be able to remotely issue orders to Flathead, the spider-like robot that V purchases from Maelstrom gang. They can steer it and issue other basic commands but it will take a techie to use the advanced commands.
Apparently, entire sections of missions can be completed by using the tiny robot alone and these sections will usually be unique and unavailable without Flathead.
Those who wanted extreme implants that can be seen on Maelstrom gang members may find themselves somewhat disappointed but this has been hinted before when CD Projekt Red stated augmentation will be limited and players will not be able to push V far enough to become a Psycho.
CD Projekt Red
On the other hand, Maelstrom members showed regular cognitive functions and were certainly aware of their identity which means they didn't push themselves over the limit either. The reason for not being able to scoop out half your face and put a blinking red light in the cavity instead is because that kind of modification would create barriers to the rest of the gameplay.
All of this info came from CDPR's Q&A on Tumblr so you can check it out for even more tidbits.