I tested out my game on my iphone6 and then I re-adjusted the gameplay. I have decided to start the game with less blocks to avoid and as the player progresses through the levels, it gets harder and the mount of blocks to avoid increases varying in speed.
The block hit count that tells the players how money shots left to destroy the block is now visible on the Gameobject itself instead of the canvas. I learnt how to do this by using 'Text Mesh' to display the text instead of the canvas.
I realised in previous builds the block fall would fall out of sync or fly away and that was because the blocks, power up and Gwap- coins where colliding with each other and shifting the blocks out of place. To fix this issue I had to change the collectables to triggers instead of colliders like the box that use physics.