To play MagNets, you must defeat Bloxbots to gain scrap. You do this with your MagNet, an electromagnetic net which zaps Bloxbots.
Press and hold LT or RT to deploy a MagNet. This drops a MagNet Marker at that point. Move away from that point and an area of electromagnetic energy will appear. Stretch out this MagNet around a bot or bots, and when you're ready, release the MagNet button! This will deploy the MagNet and zap all the bots within the circle. Careful, though: your MagNet will only stretch so far. If it gets too big it will deploy. The bigger the MagNet when deployed, the longer the recharge time. Smaller MagNets mean a better score, too.
The first deploy will only stun a Standard bot. The second deploy destroys it. Other types of bots may take more. Destroyed bots turn into scrap, which you can collect and take to the Recycletron. When full, the Recycletron will make you a useful component! Find where it goes and you will get through the level.
And don't forget to protect destructible objects! Their health is displayed inside the red targets. If they are all broken, the MAyOR will have YOU recycled!