Ill answer the first yes/no question about this puzzle made after this post.

For the sake of the puzzle, do the game titles include "Sid Meier's"? For example, is "Sid Meier's Railroads" treated simply as "Railroads"?

Thats hard to answer in a yes/no format as you dont need to know the titles to complete the giveaway. the titles could literally be labeled 1-5 and you would be fine. I may have been misleading in the previous yes/no question as the numbers 1-5 do correspond to the games its just there names are not so important.

Edit: fixed a spelling mistake

Thanks. That would've tripped me up for a while, I think.

Im heading off to bed soon. Ill answer the first yes/no question made after this post when I get up in the morning

Bump! still taking the first yes/no question

OK, here is:) Each line represents just one character?

by line I assume you mean row. if so then Yes.

Ill answer the first yes/no question about this puzzle made after this post.

Is any of the numbers in each row referring to a date (day and/or month)?

no

Ill answer the first yes/no question about this puzzle made after this post.

Do the Steam store pages for these games play a role in your puzzle?

no
I recomend you read hints 2+3 for more info ;)

Yeah, I was basing that on the heart being the 'source' of these games. Thank you.