Getting the ball rolling

All right, if I'm gonna go through with this, I'll have to decide what kind of game I'm making. A number of factors have to be taken into consideration...

What I Want:
First and foremost, the game has to be fun. If I don't enjoy playing my own game, then most other people won't either, and I might as well not make the game at all.
Second, I want it to be unique. I am not making a clone. At least to some extent, I want to make a gameplay idea that has not been seen before. Innovation. Interestingness.
Those are my big two. There are other things that I want, but they're generally either too minor or too unattainable to list. In the interest of time, let's move right on to...

What I Can't Do:
I'm working with two handicaps here: I'm by myself, and I have a time limit. That rules out the following:
-Anything with sprites or detailed models. I don't have the artistic capability.
-Music, too, is out. Sound is unlikely. These may be added in later versions, after the one-month period is over.
-Plot? If I have one, it'll be simple and minor. No epic, earth-shattering storylines. I don't have the time or skill to write them, and I don't have the time to implement them.

Okay, we have our rules. We're looking at something simplistic, yet engaging, using highly abstracted graphics (something like This Guy's stuff, perhaps?). Gee, sounds like alot of my old games. Looks like I'm making another one in the same vein.

Available genres:
Action: I have experience here. Phoenix 2X, Entropy XXIII, and Zombie City III were all passable action games. I can make another one, but I'd need a cool concept for it or I'm just flogging a horse. A dead one.
Puzzle: Haven't done much treading here. The big problem is, it's hard to come up with a fun, interesting straight-up puzzle game that hasn't already been done somewhere. That, and my audience is limited. (If you disagree, we're probably using different definitions of the genre... which brings us to:)
Action-Puzzle: Here we have our Tetris, our Dr. Mario, our Tetris Attack. This is the stuff addictions are made of. A personal favorite of mine, and a tempting choice, if I can come up with a clever concept.
RPG/Adventure: Cautious. My options are limited, considering my time and resources. Text adventure? Never made one, that'd be scary ground to tread on at this point. Roguelike? Hmm. I had some fairly extensive plans for one, but I don't know how good I'd be at making it, considering my lack of experience.

I'm not going to use any of my current or future projects. Vertical has a partially established engine, but... good lord no. It'll take me WAY over a month to complete that beast, even IF Preston would give me the sprites for it. Zombie City IV isn't sufficently planned out, and I'm pretty sure it's gonna be a big enough project that I wouldn't have the time to make it everything I want it to be. Both of those will be shelved for now.

So!

I leave it to you, whoever is reading this, to chuck some ideas at me. I don't expect to get anything really final at this stage (although I'm open to being surprised), but some suggestions should help get the wheels turnin'.