linker error while building roborobo using SDL - c++

Question

I'm using robo robo simulator. It requires SDL to be installed. SDL was successfully installed using sudo apt-get install in Ubuntu
'make' was used to compile and link.
compilation was successful but while linking I got the following linker errors
[LD] roborobo
src/core/roborobo.o: In function `clean_up()':
roborobo.cpp:(.text+0x29): undefined reference to `SDL_FreeSurface'
roborobo.cpp:(.text+0x35): undefined reference to `SDL_FreeSurface'
roborobo.cpp:(.text+0x41): undefined reference to `SDL_FreeSurface'
roborobo.cpp:(.text+0x4d): undefined reference to `SDL_FreeSurface'
roborobo.cpp:(.text+0x59): undefined reference to `SDL_FreeSurface'
src/core/roborobo.o:roborobo.cpp:(.text+0x6a): more undefined references to `SDL_FreeSurface' follow
src/core/roborobo.o: In function `checkQuitEvent()':
roborobo.cpp:(.text+0xdff): undefined reference to `SDL_PollEvent'
src/core/roborobo.o: In function `handleKeyEvent(unsigned char*)':
roborobo.cpp:(.text+0xead): undefined reference to `SDL_Delay'
roborobo.cpp:(.text+0xf1a): undefined reference to `SDL_Delay'
roborobo.cpp:(.text+0xf43): undefined reference to `SDL_Delay'
roborobo.cpp:(.text+0x1037): undefined reference to `SDL_Delay'
roborobo.cpp:(.text+0x111e): undefined reference to `SDL_Delay'
src/core/roborobo.o:roborobo.cpp:(.text+0x1191): more undefined references to `SDL_Delay' follow
and many more
SDL_gfxPrimitives.c:(.text+0x7477): undefined reference to `SDL_UnlockSurface'
SDL_gfxPrimitives.c:(.text+0x7491): undefined reference to `SDL_UpperBlit'
SDL_gfxPrimitives.c:(.text+0x74e6): undefined reference to `SDL_CreateRGBSurface'
collect2: error: ld returned 1 exit status
make: [roborobo] Error 1 (ignored)
the make file also has sdl-config --cflags --libs -lSDL_image
the Makefile is in http://pastebin.com/5EdcZWAd
the entire console output after 'make' is in http://pastebin.com/yXDHR9xw