I like puzzle games, so this game was right down my alley!
I'm going to lead with my criticisms first. I appreciate that you tried to go with a minimal, more visual instruction manual instead of a big wall of text, but it didn't work here. For example, the manual says that there are viruses that destroy particles, but it's not clear how the player is supposed to deal with them. Can they be trapped? Is your only option to run into them?
The overall design has some issues, too. For example, the player is thrust into the first map with a bunch of particles and viruses and no guarantee that they have read the instruction manual. It would be better to start off with just a few weak viruses and some quick instructions on how to deal with them. Use the opportunity to introduce the player to each major mechanic of the game a little a time. Then the levels can increase in difficulty and introduce each new type of virus. This will provide a sense of the levels getting more challenging, but the player will also feel more able to address those challenges.
Another issue lies in how the maps are laid out. When a level starts, the player may not be able to see all of the friendly cells and may not even have time to respond to the virus threats, resulting in some cells being lost no matter what the player does. There are a few different ways this could be addressed, but ultimately the goal should be to set the maps up in such a way that losses only happen due to the player's errors.
Despite these criticisms, I thoroughly enjoyed myself once I figured out how to play! If the issues could be addressed, I could see this being developed into a really good full game! I hope you continue to develop this and improve your skills.