The original storyline I had for Invasion was that some unknown alien force was invading and you took control of a special task force soldier type dude and pretty much went on a killing spree. However, I've come up with a different scenario and I'm going to be changing the title; I haven't set anything in stone yet, but as soon as I do, I'll post a writeup about it. It's still going to be a shooter-rescue type game (where you kill everything on screen while trying to rescue people) and it's still going to be about an invasion of sorts, but the main character has changed, I've added a second character, and it doesn't really have much of a storyline. I'm aiming for somewhere between 25-50 levels with an unlock-style system (where as you play levels, they're unlocked and you can start from any level at any time.) As I said, there will be two characters to choose from, one of which will be unlocked after the game's been played through once. I only have five weapons and five items slated at the moment, but that's one thing I can always add later. The enemies is what I don't have nailed-down yet, but again, that's something I can always add/remove/change later. Obviously there will be music and sound, but I'm also going to at least be giving voice to the two main characters.
So, the design is about three-quarters of the way done. Now I just need to sit down, write out everything, get my goals, milestones, and plans all worked out and then get busy. I didn't get much of anything done today other than watching Transformers 2 (which fucking rocks by the way); I didn't get home until almost 11 and I'm just now getting to my computer (about 2:30am.) I have to work the rest of the weekend, so I'll only have about 4-7 hours each night to work on it, but I'll get my stuff listed out and it'll make things go a lot quicker.
So, anyway, look forward to some content in the near future. It won't be pretty or sound good, as I'm no artist or musician, but once I start nearing the end of production I'll start looking to contract some artwork and whatnot.
I'm off to play some Oblivion before I head to bed.