I don't know SDL so I cannot you help deeply, but perhaps I found some little syntax error on compiling main.o
first of all: careful to spaces.... between "-I" options (example between 1st and 2nd one) there are 2 o more spaces..... remember that every option must be separated by one single space only
Second: (again, spaces...) when you use FLAGS (like CXXINCS) remember that first option must immediately follows the = so don't write a space from = and first -I option (becouse, after sostitution, there will be more spaces in command line)
so try to replace your CXXINCS with this one
CXXINCS=-I"C:/Dev-Cpp/lib/gcc/mingw32/3.4.2/include" -I"C:/Dev-Cpp/include/c++/3.4.2/backward" -I"C:/Dev-Cpp/include/c++/3.4.2/mingw32" -I"C:/Dev-Cpp/include/c++/3.4.2" -I"C:/SDL-1.2.15/include"
As you can note I removed also the space after "C:/SDL-1.2.15/include" becouse the final string must end WITHOUT spaces.
Another good practice, for a "flag" macro, is to don't make spaces also from macro and = (in that case it is better to write CXXINCS= instead of CXXINCS =)... unlike the other spaces, this is NOT an error, only a suggested practice (becouse in this way you would probably not forget to don't use spaces between = and first param)
Moreover.... Dev-C++ is deprecated and abandone.... mainly your version that still use gcc 3.x while now it is suggested to use gcc 4.x (better if 4.6 or 4.8)
Hope this hint can be helpful