If you are interested, this game was developed on Unity3d[unity3d.com] engine. So, most of those can be launched with command-line params, more about - see this manual[docs.unity3d.com]

1. Right-click on the game title under the Library in Steam and select Properties.
   
2. Under the General tab click the Set launch options... button
   
3. Write:
   
   -screen-width 1920 -screen-height 1080
   where 1920 and 1080 can be changed as you wish
   
4. OK, Close and launch game!

Compare result:

Like and subscribe here http://psteamproxy.yuanyoumao.com/curator/9113679/