I compile it with the mingw gcc that comes with Dev-C++ (although I use the command line rather than the IDE).
Here is a step-by-step guide to compiling it with Dev-C++ in the IDE
1) Download and install Dev-C++
2) Once it is installed, install the SDL add-on
(if Dev-C++ installed correctly, you should be able to just download the ".devpak" file and then run it).
3) Run Dev-C++, and select "File->New->Project".
4) Select "Multimedia" and make sure "SDL" is highlighted. Make it a C project, and name it "Oriculator".
5) Click "OK" and save the ".dev" file in an empty dir somewhere.
6) It'll give you a filled-in "main.c". Right click on the main.c tab and select "Close". It'll ask you if you want to save the changes to main.c, select "No".
7) Copy all the ".c" and ".h" files from oriculator into your new project directory (the same location as you selected for the Oriculator.dev project file). You don't need the makefile, just the source files.
8) Back in Dev-C++, right click on "Oriculator" in the project tab, and select "Add to project". Select all the source files and click "Open".
9) Go to Project->Project Options
10) Click on the "Parameters" tab
11) On the end of the compiler parameters (after "-Dmain=SDL_main"), put "-D__SPECIFY_SDL_DIR__", so that the compiler parameter contains:
12) Click "OK"
13) Go to File->Save All
14) Go to Execute->Compile
How to compile it using GCC from the commandline (how I do it myself)
1) Install Dev-C++ and the SDL devpak as described in steps 1 & 2 above
2) Check out the Oriculator sources
3) Edit the makefile, and make sure "PLATFORM ?= os4" is commented out, and "PLATFORM = win32" is not commented out.
3) Open a new command prompt, and CD to the place you checked out the sources
(replace "c:\dev-cpp" with where you installed Dev-C++)
5) Type "make"