Upgrade Complete II

Upgrade Complete II, developed by Armor Games in 2011, is a browser-based Flash game that challenges players to upgrade everything in the game by piloting a spaceship, destroying enemies, and earning money. The game's objective is to continuously enhance the player's spacecraft by investing in various upgrades that allow them to progress to higher levels.

One of the most notorious features of the game is the Heart Rate upgrade. This particular upgrade unleashes a startling jump scare when purchased, featuring a flashing image of a boy with a Photo Booth filter, accompanied by a piercing scream.

Upgrade Complete 3mium, the sequel to Upgrade Complete II, also has a secret jump scare. However, unlike the second game, this jump scare comes with a warning, allowing players to prepare themselves for the impending shock. This subtle yet effective change shows how the developers have taken feedback from their audience and incorporated it into their game to enhance the player experience.

Links
NOTE : The following game contains a screamer!
 * armorgames.com/play/11028/upgrade-complete-2