CS: Upgrade Gun is an arcade / casual shooter game, available as a browser (web) game, you don't need to download anything, you just play from your browser. In it you control a gun (or "living cannon") that moves automatically, shoots on its own, while you direct its movement, with the goal of shooting down enemies and surviving as long as possible.
The central dynamic revolves around the progressive improvement of the weapon: during the game you collect boosters or "upgrades" that increase your firepower, improve the cadence, damage or special effects, allowing you to face increasingly intense waves more effectively. This makes it more of an "arcade + progression + survival" type shooter than a traditional tactical FPS, the action, fast pace and accumulation of upgrades matter more than complex strategy or realism.
In addition, CS: Upgrade Gun is all about simplicity and accessibility. The controls are very direct: with a mouse on PC or touch on the screen if you play on mobile, which makes it easy for anyone to play without a high learning curve. This, along with its simple graphic style and its "pick-up-and-play" format, makes it ideal for quick games, without technical demands or the need for previous experience in shooters.
CS: Upgrade Gun offers a lighthearted experience, full of action and explosions. If you are looking for a simple, addictive shooter, where what matters is upgrading your weapon, surviving and watching your firepower grow, this title delivers perfectly, more frenetic arcade than simulation.