I've spent 20 minutes clicking, I don't know how many things I've killed, I don't know when I can start upgrading, and I don't know how many skulls I've collected. At least give us some sort of tutorial rather than a green monster hand pointing to something every once in a while.
If you are having trouble getting achievements and are on chrome, you have to click the flash icon in the address bar and let chrome allow the flash plugin. As soon as it's enabled you should be good to go. This is applicable to all the other BOTD's lately.
Like diox, I'm not getting the badge either. I'm level 7 and have definitely killed more than 20 enemies. I also can't find the "report missing achievement" link on this game. Sigh...
Ah papa, we meet again. Your terrible games that somehow keep getting BOTD are the bane to my existence. I can not one star your games fast enough and Kongregate's pimping you out is disgusting. I hate you papa. I wouldn't even wish your franchise on the likes of EA or Activision.
When the game starts slowing down go to the main screen (world map, lab, etc.) click exit and go to the main menu. Then click continue and continue playing!
Lesson learned on the shotgun.