NOTE: I don't know where original non-touhou games that are being developed by people in the community are supposed to go, so I'm sticking it here. Move if necessary.
So I'm trying to do a shoot-em-up for my first game. My "goal game" is a game that is like mixing concepts from Kingdom Hearts and Crescent Pale Mist (well, that's not the greatest description but the system description took 4 or 5 pages alone, and the story... we'd be here forever :V) but that's not what I'm writing about. I might get motiviated to type it up -- again -- later.
A shoot-em-up with a water-based system. Sounds odd? Yeah, because it is. I actually got the idea from F-Zero some how (don't ask, i can't tell you how either

) and it's not 100% finished yet. Your character relies on water some how - water magic, water-powered tech, whatever.
You have a water tank meter. As long as it's above 50% you shoot at the Touhou 10 equivalent of power level 5, which is your max power level. From there, your attack power decreases by 1 for every 10% of the guage you lose. (I'm thinking about making this gradual, instead of 10% for every power level, or maybe even making it vary by character/shot type or something. However, this works for now.) Being in focus mode makes your attacks more powerful, but drains the meter faster. Different shot types have different water usage needs. Finally, you can shoot without using your options by tapping the shot button instead of holding it. This uses no meter. Also, it'll probably be configurable between hold and two-button modes.
I wanted to do something interesting for the bombing system. That's the reason that water is used: however your character uses the water produces steam. This steam is reserved in a separate tank. As the water is used, depending on the shot type, the steam meter fills up a certain amount. Also depending on the shot type, a certain amount of steam is used to activate a bomb or deathbomb. Using a bomb pumps the steam into one of your options and overheats it, causing it to do something amazing for a short period of time, and become unusable for a short period of time afterwards, decreasing your max power level. If I decide that the focus bomb is different, it may also dip into the water tank to provide more power, but this will also deactivate the option for a longer period of time. I'm also thinking about making dying add some steam to the tank and remove some from the water tank.
Filling the water meter can be done in a couple of ways. First, in preset areas of each stage, a stream falls. Fly through the stream to fill up your water. Staying in a stream constantly will get you points, but restrict you from moving on either the X or Y axis depending on where its coming from. You can think of them like the recharge strips in F-Zero games.
Certain bullets, when grazed, refil the meter a little bit. And other bullets can be collected. Due to collectable bullets, otherwise impossible patterns can be dodged through (think Ikaruga, but only with one color).
Some enemies can drop their own tanks and you can collect them to refil your own. The less of the water they use the more you get to keep for yourself.
Depending on the area, not all of these will be (or can be) used.
I'm debating a Mega Man-style game flow where you start with an intro stage, get to pick the order of the next 6 stages with the obligatory crisis stage in the middle of the game, and the final area. You'd get different options from each boss.
The game would save after each stage (if you tell it to) and offer to save a replay. Whether or not the Mega Man-style select thing is implimented, saving between stages, continuing later, starting a new game if desired, and a mode without saving or stage select for score ranking and replay saving will be.
So, what do you think? I'm open for suggestions (especially on whether the Mega Man thing is a good idea; I've been wanting to see a shoot-em-up do it for a long time but I don't know if I should just save that for another project).