If you've ever eaten Strawberries and Pears then Guava fruit tastes like a Combination of Strawberries and Pears.
Guava is a very delicious fruit and it has a strong flavor but very mild taste with a dense texture to it.
Also depending on the ripeness of the Guava fruit it can have either a sweet taste to it or a sour taste to it.
Either way I find Guava Fruit delicious and Guava Fruit is also a very healthy fruit for you.