As Krashen says in Foreign Language Education – The Easy Way:
…the system of grammar, vocabulary, etc. that needs to be acquired is too complex to be learned consciously….(p. 7).
In other words, there are too many combinations of bricks for the mind to build the house of acquisition by using the medium of analysis and conscious organization of each word that occurs in speech. Reading the grammar and hearing the language spoken in meaningful and interesting ways allows the unconscious wiring to organize all that information.
This is called wholistic learning. We first hear and read the grammar and we get it without using the conscious mind, then when the unconscious has the bricks it needs, it builds the speech and the writing pieces. We do not label each brick in the house as per its grammatical category of relative pronouns or whatever. Doing that is vastly inefficient. Doing anything (technology games, activities, etc.) that is not directed at the unconscious minds of the students is vastly inefficient.