This is classic bombdodger game. Click on the green tiles to dig them. If tile becomes red, you hit a bomb and lost. If tile becomes brown, you are safe. Number on the brown tile shows number of bombs nearby. There are two modes: shovel and flag, which can be switched to each other by pressing "space". In the shovel mode, you can dig tiles, and in flag mode, you can mark some tiles where you think there are bombs.
This is some kind of copied from "Google Play Games" game on the mobile.