I've started working on a small challenge level. It's actually not so much about challenge, but about the passage of time, which I hope to implement as realistically as possible. For example, after you pass through an area where snow is falling, upon your return to the area you'll see snow deposits on the ground, and some of the enemies will hide and others will emerge. You start the game in late afternoon, and as you progress, the sun is slowly setting, the place is getting darker and again, some critters disappear while others appear. And so on. I have two areas more or less completed, and plan on adding at least two more; maybe expanding one of the ones already completed.
No idea when I finish this, sorry. May take quite a while, may take only a couple of weeks. The forum won't let me attach screenshots ("upload folder is full", eh?),
so here are links to two screenshots:
http://funkyimg.com/u2/484/377/complacency-1.png
http://funkyimg.com/u2/215/138/complacency-2.pngApparently the image upload service I've chosen doesn't tolerate linking from here. So here, hopefully, are the screenshots, now uploaded to my own website.
Boy, what an ill-fated beginning for an unassuming little level.