What's popular and fun nowadays?
It depends on who you're asking, actually. Dating sims have always been popular though some find stat-raising DSs fun while others do not. It really depends on who your target audience is.
How simple is too simple?
I don't mind if a game is so simple that almost everything is just fluff, but it has to have an actual story that binds everything together. A game with no such thing (just a plain stat-raiser, for example) is way too simple, in my opinion. So simple that it could even be, I dare say, boring.
How would I know if an idea is worth fleshing out?
If you ask me, I think ideas are worth fleshing out if you WANT to flesh them out.

There are a gazillion ideas in the world, waiting to be fleshed out. Who are you to deny their existence as a well fleshed-out idea?
And if I do flesh out an idea, how do I keep the complexity down so that I can still manage it with my still low skill level?
Keep the characters to a minimum (if you're making an otome, 2-3 obtainables is a nice, easy number), and try not to branch out the paths too much. A fairly linear story with some branching out (for a few different endings) would do the trick for a first game.
What would you guys suggest when creating one's first project?
As an otome writer, I say... KISS. Keep it Short and... no, not simple. Sweet. Hahaha. =) Don't be scared into investing your feelings into making the game, and I swear it'll come out in the form of a completed project.
And, since I want to get inspired, how was your first experience creating like?
My first game was a short otome created in about a week. It was really fun. I did the outlines on the first day, scoured the internet for free art and music on the second day, and wrote and coded the whole script within the next 4 days. Back then, I had absolutely no idea how to code, so I was learning all throughout the process of making my first game. I was a high school student on my summer vacation, so sleeping late was something I enjoyed. =) It was really, really fun.
Oh hey there! (I need your thoughts. A part of me is thinking about writing in Filipino, but I've this nagging feeling that I'm best off scrapping what I've got so far and writing purely in English. With current trends, the original language version might have little to no audience until I finish a translation. What to do, oh what to do.)
And oh my gosh, you're a Filipino too! Yay, that's nice.
I know your reply was meant for riiko08, but... I just want to say, "Go for it!" My first game is actually set in the Philippines, and believe it or not, a lot of the players were Filipinos too! (At least, that's what I think, since the ones who left comments on my game development blog were mostly Filipino) Some were actually asking me to make a translation for the game, and one even offered to do the translation. It was really overwhelming, and I'm super grateful for our fellow Pinoys/Pinays for the support. I say, if you really want to create a game in Filipino, then go do so! Based on my experience, I think it's safe to say that we come from a very supportive nation, hahaha. Besides, you can always translate it into English afterwards, right?
Good luck on your visual novel-making journey!
