If you are looking for a game to play while killing time, try to play Dino Shift 2. It is a fun game to play where you will help the little Dino collect the required number of blocks and reach his portal. You will find the number of blocks required at the upper left corner of the screen.
There are three kinds of blocks: pink, green and blue. To get them, press the corresponding letters where Letter Z is for green, Letter Xfor blue and Letter C for pink. Time is limitless but the Little Dino must have collected the blocks before going to his portal for the portal will not work if he has not collected the required number of blocks. There are obstacles too along the way. The little Dino must avoid stepping or falling on the spikes. When he meets some creatures, he must step on them.