This is a 2D shooter io game called Build Royale. To beat all of your enemies, you have to build and loot to improve your guns.
After getting ready, you'll be taken to a lounge. In the room before the game, you can play soccer or basketball, practice your building with 100 of each material, and talk to other people in the lobby. Once there are enough players, you will be put into the match at a random location on the map. To get ready to fight, you must open boxes and pick up items from the ground. Getting materials is another important part of the early game. Wood can be found in trees, tables, chairs, and other places. Brick can be found in rocks, and metal is the hardest and best kind of object to find and use. Always keep an eye on the map with M as the game goes on, because the red storm will be closing in slowly. You will take damage if you get caught in the storm, but the damage slowly builds up over time, so getting caught in it at the start isn't a big deal. Also, make sure you have lots of heals on hand in case you get hit by a bullet or get caught in a storm. If you can build and shoot well enough and stay alive long enough, you might win the game or come in second or third place.
Have fun and good luck!