I find a strategy in Scarlet Skips that lets me reach high loop counts. I achieve it after focusing on luck, jump height, and rocket boots. With the right upgrades and a few jump ropes, I keep gaining upgrades and eventually stay in the air without coming back down.
Strategy
I discovered this strategy fairly early in the game and managed to reach around 200,000 loops before my game crashed. Here is what I did.
The Actual Strategy
I start by playing the game normally and prioritizing luck, jump height, and rocket boots once I unlock them.
I only need around two to four jump ropes. I focus on grinding jump height and luck first. I reinforce and add more jump ropes later, but it is not necessary. Rocket boots are not very useful at the beginning, so I focus on jump height and luck and upgrade the rocket boots later.
After some grinding, I reach a point where I jump high enough to get multiple loops from a single jump. With enough luck, I also start getting multiple upgrades from one jump.
I notice that the rocket boots reset their fuel whenever I get an upgrade. With around two to four jump ropes, about twelve loops per jump, and enough luck, I start getting multiple upgrades. I immediately hold down to use the rocket fuel every time, which lets me get even more upgrades during each jump.
Once I upgrade my jump height and rocket boots enough to get multiple upgrades per cycle, I start spending upgrades on jump ropes and speed. At this point, any jump ropes I break easily be replaced by the number of upgrades I get from a single jump.
After upgrading the rocket boots further, I reach a point where I keep holding down and continue going upward without running out of fuel.
I then start upgrading to fire jump ropes and adding more jump ropes. I continue upgrading the rocket boots so I do not run out of fuel, since the requirement for the next upgrade keeps increasing.
I am not completely sure, but I think rope speed and luck eventually reach their maximum. Once they do, I focus on fire, rocket fuel, and adding jump ropes whenever those cards appear.
Once I get into this cycle, I keep holding rocket fuel and getting upgrades without ever coming back down.
I reached around 200,000 loops before my game crashed. My laptop is fairly slow and weak, so it may be possible to go even further.