I hope you enjoy it! ^^ To make things easier to read, I'm going to break up my answers to your questions with a "---"
Yes, we are going to make a second game in the series. We're planning on making 3 games in the DFU series.
When you finish the first game, it will ask you to make a completion save file. This save file can be transferred into future games to affect how the story continues in the series. If you do not have a completion save file, you will be able to start the next game by making some quick choices that determine what happened in a previous game.
Each DFU game will have their own contained storyline, as well as some arcs that will continue throughout all three games. Kinda like if you reading a trilogy of novels.
I do not have a detailed walkthrough completed at this time, but I have a general tips page on my tumblr that will give you a basic idea on how to end up on a character's route. You can find that here.
If you are looking for help with achievements, there's a page here that has each achievement listed and how you unlock it. If you haven't completed the game yet, there will be possible spoilers on that page.
If you need specific help, feel free to email me at destinyfailsus @ gmail.com (remove the spaces) or messaging me on twitter @DestinyFailsUs. I'll reply as soon as I can ^^
When the game was released, I made some updates to fix things in the game. The version you downloaded should've been 1.0.2, which is the latest version of the game. That's why there's an error, there's nothing to update at the moment. :D
If I do fix anything else, you will be able to update it and play it via the Update button on the title screen. At the moment, I do not have any specific plans for an update.
If you were curious and wanted to see what was fixed in a previous update, or if I do update the game in the future, I post about what was changed in the game here.
Hopefully this answered some of your questions. :D
I hope you have an awesome weekend! ^^ Have fun playing Destiny Fails Us: A New Life ~ ^^