What is google's policy regarding the images of the apps? I want to use the Images of the apps that are shared by the developers for displaying on the Google Play Store (The app/game screenshots).

Am I allowed to use them? Can they be reproduced?
Please read the terms and conditions of the site, specifically, under sub-heading 6. Rights and Restrictions, and I'll quote:


  No Public Performance. You agree not to display content contained in
  Products in whole or in part as part of any public performance or
  display even if no fee is charged (except where such use would not
  constitute a copyright infringement). Use of a tool or feature
  provided as an authorized part of Google Play (for example, “Social
  Recommendations”, as defined in the Music terms below) is permitted,
  provided that as you use the tool or feature as specifically permitted
  and only in the exact manner specified and enabled by Google.
  
  Capturing of Streams. You may not use Google Play or any Product in
  conjunction with any stream-ripping, stream capture or similar
  software to record or create a copy of any Product that is presented
  to you in streaming format.
  
  Sharing. You may not use Products as part of any service for sharing,
  lending or multi-person use, or for the purpose of any other
  institution, except as specifically permitted and only in the exact
  manner specified and enabled by Google (for example, through “Social
  Recommendations”).
  
  Proprietary Notices. You may not remove any watermarks, labels or
  other legal or proprietary notices included in any Product, and you
  may not attempt to modify any Products obtained through Google Play,
  including any modification for the purpose of disguising or changing
  any indications of the ownership or source of a Product.


The italic-ized and bolded heading is my emphasis and thus would lead to OP's intention to be in violation!