Ths standalone version of top-down run 'n' gun game Venusian Vengeance is now on Steam.  Venusian Vengeance was serialized as 5 in-browser episodes here on Newgrounds a year back.  The new Steam version contains the full game, as well as an all-new hard mode, which has faster enemies and tougher encounters.

You can get the game on Steam here:  http://store.steampowered.com/app/351240/