Helpful tip for all the folks grinding for hard badge. I found it quite easy to get 25,000 points mostly by killing ghosts. At lvl 1 nad 2 there are not so many of them so all you need to do is to dodge them for some time and wait till they group up. When they do you take power-up and kill all 3-4 of them. After this you wait for them to respawn and kill them again. Try not to rush advancing to next level, take your time and grind points. You can easily get 25k on level 3. Hope this would help ya! :)
'END DAY' button is so close to 'DIG' that it is really easy to click it by mistake and return too early. Plz add confirmation if you got some spare time just like in f.e. HoM&M series