So, it all starts with useful microparticles-granules, and then develops into eating bacteria from other players. Start with balls smaller than yours, because they are simply easier to destroy. However, smaller bacteria are more maneuverable than large and heavy ones, which are harder to escape from you, but also more difficult to destroy by close encounters.
If the bacteria do not want to come close to you in any way, shoot at those smaller ones with small particles, this will attract the attention of potential rivals, and you will be able to destroy them when they approach you.
There are subtleties known exclusively to experienced gamers: if you are attacked at times by a larger bacterium, you can safely hide behind green bacteria with small spikes. If the situation is already too critical, press the letter W five times and then you will be able to shoot the enemy. Or there is another trick: if the enemy is too close, and it is very large, press the space bar to divide the bacterium into 2 parts. And while the giant will destroy one cell, the second will be able to slip away.