《槍口》屬于動作RPG游戲，在該游戲中，玩家將會扮演一位秘密偵探潛入到敵人內部作戰，游戲元素豐富新穎，在2D渲染下的游戲畫面精美細膩，背景音樂輕松詼諧，該補丁為3號升級檔補丁，用法如下。

使用說明：

1、解壓縮文件
2、安裝升級補丁
3、運行游戲

更新說明：

Bug fixes

- You can't change the past. At least, you can't change more than the first 11 missions of the past. At least, you can't if you don't have a scroll wheel on your mouse. At least, you couldn't until this patch, which fixes that. The Up and Down keys (W/S) now work to scroll through the Previous Missions menu.

- With apologies to Mad Men fans, knocking the final boss through his own office window no longer causes him to fall in extreme slow motion.

- If you bought so many batteries that you can no longer afford the Gatecrashers needed for the final mission, a) wow, and b) you can now sell batteries at that point. Unless your battery fixation prevents you from parting with them, in which case your adventure ends here.

- Due to new breakthroughs in microphone technology, Sound Detectors are now so sensitive they can even pick up gunshots. (They previously only triggered if the player was the one who fired).

- Did you know you can patch a soundtrack? We patched the soundtrack so that the track numbering makes more sense for the Special Edition.

- You can no longer teleport backwards through left-facing windows by pressing Down. Sorry speedrunners.

New features

- If you're having music problems, I feel bad for you son. So I'm working hard to fix them, and in the meantime I've added a button to restart the music: press M if you're not hearing music and should be.