Unlike the original games from Chronicles of Mystery group which were typical 3rd-person point-and-click adventure style, Secret of the Lost Kingdom switches to hidden-object gameplay style. The protagonist of the game is no longer Sylvie, but instead you control Chelsea. She lost her father when he was on an expedition in Africa, and recently she got entangled in a dangerous situation with Menekot, a megalomaniac trying to find a long-forgotten relic that he believes will give him the power to rule Africa as a rightful heir of king Solomon himself. Barely escaped with her life, Chelsea travels to Alexandria hoping to find the relic before Menekot and find a way to exact vengeance to her father's murderer.
Game uses 1st-person perspective and lets you travel through limited number of locations during your investigation. point or person of interest is always marked with sparkling effect which either starts a dialogue or a mini-game that progresses the story. Mini-games consist of assembling broken tiles, looking for a pair of identical items as a game of memory, searching for differences between the images (usually the actual image and a reflection in a mirror or a water pond), typical hidden-object scenes and other puzzles. Hidden-object scenes are all timed and will often reuse locations with different items scattered about. You can also find diamonds which can be traded in order to skip puzzles. Chelsea also keeps her journal which contains story of her journey thus far as well as all the in-game dialogues and cutscenes. Voice-acting is only present in intro and outro, while the in-game dialogues contain only text.