The phrase "equal parts fun" means that something is a combination of two equal amounts of enjoyment or enjoyment that is split evenly. Full definition
I'm a firm believer of equal parts fun, clean food, and exercise while still enjoying my chocolate molten lava cake with vanilla bean ice cream! (nutritionexpert.com)
This gal is beyond ready for a getaway with equal parts fun in the sun and R&R. (26andnotcounting.com)
Nuclear Throne sounds like equal parts fun and enraging, but a game where player skill waxes strong with every failed run — signs of a true roguelike. (buttonmashing.com)