Fixed compiling on linux

CMakeLists.txt

@@ -25,8 +25,13 @@ else()
   message(FATAL_ERROR "Missing or invalid definition of TARGET_TYPE")
 endif()
 
+# Check game has been defined
+if(NOT DEFINED TARGET_GAME)
+  message(FATAL_ERROR "Missing or invalid definition of TARGET_GAME")
+endif()
+
 # Set up the project
-project(${TARGET_NAME} VERSION 1.0)
+project(${TARGET_NAME} C)
 add_executable(${PROJECT_NAME})
 
 # Variables