They developed this game <for> <over> <in> six years.

[GhotiO |fɪʃ|]

Which of these are possible?

1. They developed this game for six years.
2. They developed this game over six years.
3. They developed this game in six years.

I can't clearly see the difference between 2 and 3 (the ones with "over" and "in), but I feel those two are possible and given this fact, I'd like to ask, is 1 possible as well? I mean, if somebody (has) developed something then it's developed (finished), right?

 

[emsr2d2]

They're all possible. #1 and #2 tell us that they probably worked fairly constantly on developing the game for those six unspecified years. #3 tells us only that six years passed between starting development and finishing it. For example, they might have started developing it in 2018, worked on it for six months, shelved it for five years, picked it up again in late 2023 and finished it up in early 2024. That would be covered by "in six years".

 

[jutfrank]

When you ask what is 'possible', I interpret that to be asking about what is grammatical and makes sense. If that's what you mean, then all three sentences are possible.

However, since different prepositions have different meanings, the time frame of six years is seen differently in each case with respect to the aspect of the verb 'develop'. My interpretation of these sentences is this:

1. They developed this game for six years.

We know that development happened for a period of six years. We don't know whether they started or finished development at the beginning or end of this timeframe.

2. They developed this game over six years.

We are quite sure that development started at the beginning of the period and was complete at the end of the period. This interpretation comes largely from the preposition over, which carries the idea of a span of time.

3. They developed this game in six years.

Here we are most sure that development started at the beginning of the period and was complete at the end of the period. The preposition in carries the idea that the time frame is a kind of container within which all development happened.

 

[teechar]

They developed this game for six years.

That doesn't sound great to me. A better alternative would be:
"They spent six years developing that game".

 

[jutfrank]

That doesn't sound great to me.

I completely agree.

 

[Flask]

1. They developed this game for six years.

. . . I'd like to ask, is 1 possible as well? I mean, if somebody (has) developed something then it's developed (finished), right?

Like many others in this thread, I don't think that (1) sounds great. But we're assuming that this is a game that was developed once and for all in/over a period of six years: it took them six years to develop this game.

If we suppose, on the other hand, that they put this game through a number of different editions, or iterative developments, that is a process which could indeed be carried on for a period of six years.

I'm about to teach a reading and writing class with a textbook (Subject and Strategy: A Writer's Reader) that is now in its sixteenth edition (2022). The first edition was published in 1977, when I was one year old.

I think it could be said that the authors have been developing this textbook (putting it through different iterations of development, or editions) for forty-seven years. That's dedication!

 

[teechar]

If we suppose, on the other hand, that they put this game through a number of different editions, or iterative developments, that is a process which could indeed be carried on for a period of six years.

True. For example:
They developed this game for six years, during which several editions were produced, but the project was eventually axed in 2020.