One Button Games 5-in-1

As you keep playing (assuming you don't die), you will level up automatically around every 10-15 seconds. You'll be able to tell when you level up because the game speed will increase. As the game gets faster, it will become harder to survive, but it's not too difficult. My strategy was to ignore the character on the right and focus on the character on the left, and try to keep it as centered as possible. As long as you keep it as central as you can, you will be pretty much guaranteed to avoid the walls on either side. I'd also recommend ignoring the coin bags and doing achievements related to those separately.