Well, the bigger pictures of the enemies seem to strike a good middle-ground between input and result. Not that I would be any expert on anatomy or perspective, but they do have enough detail to look close enough. What I somehow like, is that you only used 2 colours for the main body - for that "lack" of colour, the result is really nice. Should also serve to keep your workload more limited. Obviously one can always pay more attention to detail, but that often enough tends to put the cart before the horse. The smaller sprites are also solid pixeling. All in all, a good approach, I'd say.
One word of advice. Drawing a new background or landscape every time, gets tiring re~al quick. Since you already have those "mini"sprites, I would suggest a somewhat gamey 2D enviroment. Objectives' ISG Asperge actually is a good example of what I would go for, given the resources you have shown.
Take a look at it.A good case study, and solid art, if I may say so. Taking a closer look, we have The Sky, A Horizon and Middle Backdrop, and the Pathway Area.
All you really have to do, is to change the Pathway once you come to the "border", and move the middle backdrop for a few pixles. You can easily go for rather gorgeous sky and backdrops, which you all can use for a multitude of turns - making any effort put into them time well spent. Unless you truly look for it, or someone points it out like I just did, no-one will notice either! Nor care about it in a negative way. Re-used a couple of times or not, eye-candy stays eye-candy.
No, not that kind. Doh.The only thing you have to draw each turn - and that is, if you have changed Locations - is the Pathway Area. Since it is the smallest portion of the picture, it is also the least amount of work. If anything, I really like it.
On to the next point;
Having gm'ed - and failed ;3 - a few games of my own, I am of the opinion that much of it boils down to the system you set into place. The more simple it is, the better. Chances are the only one to ever truly get behind it, is you yourself truly. In suggestion games, players don't really come looking for a rpg with finely crafted mechanics, but a story that you tell them.
Less is more in this case, really. Instead of rolling for half an hour each turn, you are better off using that time to make your posts more descriptive, or throw out updates more regularly. We even have / had gm's, who went without any system at all, or alleged to finally using anything else but their whims after close to hundred updates. Not like anybody was ever bothered by it either.
Start off with a prologue post, that basically explains how the world went to shit. Jump to the first PC, let shenanigains happen, make sure you can railroad it if need be.
Actually, the less of a story told in the beginning, the better. No, really. A snappy introduction that gets right to the point with a few sentences, is worth more than any great story you would like to tell. Dawdle around too much with the introduction, and people will be turned off and away by the wall of text. You can always get more of the lore done, once they have invested into the game, but giving it out in small portions instead of a dump normally works best.
I don't think that the story itself will be too much of an issue, since I already pretty much know what it will be. I just need to find places to insert story into among all the shenanigans that arise from suggestion games. I could however do with some tips on pacing and such.
Not sure what kind of pacing you are asking for, but using colours and glow to spice up the atmosphere of a post, works wonders. Heck, even suggestions that have some colourful flair worked into them, are more prone to getting picked - well, at least by my observation.
If you are asking for pacing of text, I'd recommend a look at Shadenights Overlord.
Here you go. See how much he writes in the later updates, and how easy it is to read, despite being an awfull lot of text at times? That is what I would understand as good pacing. Obviously the writing itself is also top-notch, but that way of arranging the text, is something one can emulate without being as good a writer as he is.