I tried the one where you don't get the upgraded rocket launcher at all or pick-up rocket ammo and then open the final chest at the end which gives a regular rocket launcher with 100 ammo, not very powerful x.x. I still like the machine gun the most, even more than the spur because you can also use it as an emergency jet pack along with the easy to hold constant rate of fire. The only bad thing about the machine gun is that the stand by time for it to recharge is about 8 seconds I think.