Hello,
Can you please explain why in this exercise it is only correct to use preterito imperfecto in the third sentence: Teníamos que conseguir muchos puntos para acceder al tesoro escondido - even though the story starts in the indefinido tense. A few sentences later it jumps again to indefinido: Este juego nos ayudó a ser pacientes - while the rest of the sentences are in the imperfecto tense.
Thank you :)