Roach Toaster has all the hallmarks of amateur design, including occasionally awkward UI issues (no undo? gah...), art that barely qualifies as more than "programmer art," a readme that is notably unhelpful, and so on. Not that we care about this, really, except to point out that most of the amateur-created games we encounter are also, well, you know, basically imitative drivel -- yet another platformer/third-person shooter/take on Space Invaders/my tedious life as an adventure game. (Actually the last sounds interesting... I actually want to see teen angst in IF, if never again in fanfic.)
I digress too easily. Anyway, the point here is that Roach Toaster is actually original. It reminds me a little bit of DROD -- not with the same depth and complexity, but in the sense of an algorithmically-driven, turn-based puzzle game.
Each Roach Toaster is a square-tesselated screen with "your base" in one square, some squares impassable, and some others occupied by starting roaches. Each turn, each roach reproduces, placing another roach in an adjoining square (if space is available); if multiple spaces are available, they spawn into a random adjacent one. Your job is to clear the level of roaches, which you do by purchasing units. The basic unit fires once in a straight line, with a range of 7 squares. Initially, only squares adjoining to your base can be placed in, but this region expands by one space each turn. Once placed, units never move.
Additional units types -- some six different types -- have different capabilities. The kicker is that, since you are an exterminator and there's a limit to how much you can charge your clients, there's a strict limit on how much "money" you can spend in a level purchasing units. The levels (25 of them) get more difficult over time, so figuring out how to defeat the exoskeletal menace within your budget requires thought and planning.
For a little 2 meg download, it's not bad at all.