chocolate covered broccoli
Merely adding gameplay to a boring task won’t make it fun or effective, just like adding chocolate to broccoli won’t make it tasty. You need to your gameplay to align with and support the themes that you are trying to portray via endogenous design
For example, Review Of Trends In Serious Gaming For Education-Young found that a history game was ineffective. The game added the historical information as “interesting tidbits” on top of the game, rather than having the history be important to the gameplay itself.