It's a great idea ! What you managed to make works really well, especially if you have no experience it's very promising, I hope you liked it and want to continue.
For information, you can bind controls to physical keys so that WASD becomes ZQSD in AZERTY keyboards (it's ok here because arrows work)
I think you coult try to make the cannons appear a second before they shoot, this way you have ample time to dodge you just have to move quickly to a safe spot (even if it means adding more cannons for difficulty). Because right now I'd say the best strategy is to stay at the end of a line and hope a cannon doesn't shoot when you go for a coin.
But still the speeds are well balanced and I grinded quite a bit to try to get a score I'm happy with (120 seconds ~20-30 coins?)