I would like to get your view on what you consider the most time-consuming steps in games development and what you think adds the most value in your games but might be difficult to achieve.
Development stories from the community are also much appreciated.
I'm an hobbyist indie developer trying to go commercially indie.
What do you consider the most important in a game?
Atmosphere and exploration - depends on personal taste
Followed by world background and character plot
[Edit:] Ofcourse, this is after gameplay, as ApochPiQ mentions below. I'm assuming the 'game' part of the game is actually enjoyable.
What takes the most time during development of your games?
Programming
What could advance your games to the next level?
Good art and music and sound effects
Where's the options for "enjoyable gameplay"?
That, and nothing else, is what is most important in games.
... and therefore its "selected by default". As its kind of the mandatory answer there is no point in adding it to the poll, is there? 
Edit: In general, "game concept" should cover "enjoyable gameplay" as the concept should make sure the game is fun to play.
"You must cast your vote in each question of the poll." :/ I would have preferred to have answered for the first question only, the others were very balanced and really didn't need any answers checked.
Anyway a good game for me is something challenging, has a great storyline (think Eternal Darkness, Tales of Symphonia etc) and has great music (WoW for example).
I am more into MMOs than anything and stopped playing games hardcore years ago, sadly too many games are dumbed down and mimic WoW in the worst possible way, sometimes I think the people in charge of decisions only got to the position they are in by having a lot of shares in the company.
"You must cast your vote in each question of the poll." :/ I would have preferred to have answered for the first question only, the others were very balanced and really didn't need any answers checked.
I agree that all aspects are important to a game. Anyhow, I am interested in personal views and flavours on the topic especially what developers find personally the most challenging.
most important:
probably a reasonably well-implemented game, that also has good gameplay.
basically, if the game is buggy/broken/... this isn't really good.
nor is having things sufficiently kludged and brittle that things barely work as-is.
programming and artwork tend to take up a big chunk of the time IME (though in my case, programming tends to dominate).
the main thing that is lacking:
that the gameplay doesn't suck...
but, it is sort of a mystery of "how will I best go about making things better?...".
basically, it is a problem of sucky gameplay and boring worlds...
Rather than "stunning graphics" I would have gladly settled for "adequate graphics" in my games :)
I can make fairly entertaining games without much difficulty, but I have no talent whatsoever at graphical design.
