Hey Peregrinus, I'll have to be blunt; games are a hard sell
If you really want to be successful, you need to show people something they have never seen before. If I was to develop a game, I would take inspiration from Mount and Blade, this was before kickstarter, when the term "shareware" was still used. Not saying you make a clone of it, but study how it got its success.
It began as a husband and wife project, two people, and no one would publish it. So they put a beta online going "this is what we have, if you like it, support us", and people loved it alright - because it gave people something they have not seen before - mounted combat. Not just that, they did it SO WELL that even its competitors can't beat them even after people finally understood there was a real demand there. Also, people didn't just play the game, they MODDED it. They had a modding community even in freakin beta, buying M&B granted people not just 1 game, but 20+ games full of total conversions from historical eras, fantasy eras, etc. You can go on crusades, fight to be shogun, and more, using mods.
As for marketing, it was all word of mouth, I never even seen a M&B popup ad online or anything, I found out about it while modding Rome Total War in the Chivalry TW project. So it's like any business, if you want to penetrate the market, you need a product that people have not seen before, and you need to examine the target market, as a TW fan I was in the target market. Taleworlds had poor marketing, it was all word of mouth, if it wasn't for the forums I may never have heard of the game.
Speaking of target market, as with any business the target market has to be sizeable, puzzle games do not unfortunately have a sizeable market anymore IMO, unlike genres such as TBSs/ REAL cRPGs - where it's more of a case of poor market research.
I'm actually wondering how Portal got away with it being a puzzle game, but I guess it had its own innovations. I never played it though.
Also, our standards as gamers have gone quite high, I only buy games that I will play, smaller games on my phone but I hardly ever play it. For my PC I want a full fledged experience, and it doesn't mean it has to be graphically awesome, but it needs to be something I haven't seen before or there's not enough of.
Personally If I was to break into the industry, I'll look at the demand, what haven't I played before or what I haven't I seen for a long time - and what I reckon has a sizable market. Take Star Generals for example, the game had space AND land battles. Even the team at Stardock failed to deliver on the latter with GC3, so my "klendathu drops" ingame are a little disappointing even though I enjoy GC3 itself. Still, GC3 got me to buy for that "modern star general" experience.
What got me in the mood for it was actually the film Starship Troopers, ever watched a film set in an era - then feel like wanting to play a game set in that era when you went home? So yeah, non-violent games are not so popular. Unless maybe if it's a detective game. There's still a few click-adventure games out there too.
There's a reason alot of talent sticks to modding games rather than publishing their own games mate, it's a tough industry. So don't feel so bad, it's your first project after all.
You're alot braver than most of us!!!!