Okay, I've upped the amount of sharks that can be spawned for level 8 and up, but how many rise up to attack will be limited by the rule that prevents three at the same time (or the player will have no where to go to evade them). I've kept the cap at level 14 since increasing the speed won't solve the problem of the amount of sharks. Hopefully this change means a few more sharks will rise to attack and make it difficult enough from level 14 onwards. Otherwise, I think the only way to make the game harder for you is to play it blind folded ;-)
Viewing post in Tomy Sky Attack
It's at the max already. There's probably something else that needs to be tweaked to rebalance the game at these speeds, but given I don't have a way to play the original game myself it's going to be hard to nail down. I think taking a break from it for while and then relooking at it again at some point in the future might help. Fortunately most people will still be able to enjoy the game without hitting this problem.
I went back to studying the original and i noticed that some sharks when they reach the player spot hang there for a little longer than normal maybe like 10% of the time and others disappear quicker than normal as well and other sharks "join that queue" going up the channel towards the player taking longer for that channel to clear which will make it harder. I don't expect you to do it now and I totally understand you wanting to take a long break from it, hope this helps :) Cheers
my skill level at its finest lol 6,625 (lvl 29) unedited video, thought i'd post this as it might give you other ideas as well :) https://gofile.io/d/R3stln