I got to lv 42 by making it a 2 player, keep only 1 entrance open, and keep constantly throwing grenades. When one player is almost out, try to get more while the other player keeps throwing. Might take a while, but it works.
Easy Card, i made hardest difficulty with all the things checked for higher multiplier, then just walked around exploring instead of fighting, and used the scrolls that make you pass 1 enemy to also not fight. Pretty easy.
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 "Boxhead: 2Play Rooms"){kind=icon}
 "Hover Bot Arena"){kind=icon}
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