Although "Fallout 4" was only recently released across different platforms, players keep on discovering new hidden secrets in Bethesda's post-apocalyptic survival title.

According to Kotaku, a modder player managed to discover a hidden harpoon gun in the latest "Fallout" installment. Although the harpoon has already been featured in other titles like "Fallout: New Vegas," the harpoon gun in the latest installment had a curious tweak – it also features underwater bubble animation.

In a report by PC Gamer, the water bubbles apparently indicate an underwater combat feature in "Fallout 4." Although players still have to discover if there is indeed an underwater mission in the Commonwealth, observers also guess that Bethesda might have incorporated the harpoon gun in upcoming DLC, and it was not meant to be accidentally discovered in this early stage.

"Fallout 4" continues to be a throve for hidden secrets and Easter eggs for players to find. Just recently, it was reported that there is a developer room also incorporated in the newest "Fallout" title, similar to what Bethesda did when it launched another big-name franchise, "The Elder Scrolls V: Skyrim." The developer room contains almost all in-game items, gear, and weapons in "Fallout 4," and players can choose to empty the room of its contents. In the case of hardcore players "Fallout," the developer room apparently can be a sort of checklist to see what they still have to scavenge and collect in the Wastelands.

Meanwhile, although the title still has secrets to be discovered, it still not immune to bugs and glitches. Bethesda hoped to plug the first of the glitches with a first-ever patch for "Fallout 4" by next week. However, the rollout for the update will be by schedule – the PC versions will receive the newest patch first, before being released for the PlayStation 4 and Xbox One.

"Fallout 4" launched earlier this month across all platforms, and has become an overnight success. Bethesda has been reported to have shipped at least 12 million copies worldwide in just Day One of the opening release.