sweet half life routes:
													  	     normal route  -> shl11 -> shl12 -> shl13 -> shl14 ---------------------->shl14b   
															          |								    |	
t0a0 -> shlwork -> shl0 -> shl1 -> shl2 -> shl3 -> shl4 -> shl5 -> shl6 -> sh6b -> sh6(again) -> sh7 -> sh8 -> sh9 -> shl9b-> sh10          					 		     -> shl15 -> shl16 (different ending depending on the route you choose)
								       							          |								    |
														      alien route  -> shl_ship -> shl_ship2 -> shl_ship3 -> shl_ship4 -> shl_2001 ->


Note: if you play in a listen server from shl6b you wont go back to shl6. Instead you will go directly to shl7. This is needed because listen servers do not support global vars.