Epic Combo is a game that's all about making epic combos.
Since that's less self-explanatory than it might be, I suppose I'll explain.
In Epic Combo, you start "combos" by hitting turtles with a hammer. The size of the combo is determined by how many times the shell or shells hit something other than the floor before the combo timer runs out; each time a shell does, the timer is renewed. Your goal in regular gameplay is to achieve 10,000 hits in one combo.
This is not actually that hard. In fact, according to the high scores list, some people achieved it in one second, though that should be completely impossible.
Anyway, when I say it's easier to reach 10,000 than it sounds, that's because you've got various tools to help, and each combo earns you money to buy these tools. (You can also buy an increased turtle appearance rate.) It's no harder, in my opinion, to approach numbers like this one...
...than it is to hit 10,000.
In fact, the very next go took me to close to ten times that total.
There are only two limitations (from what I can tell) on how high you can go. One seems to be related to the amount of time you're willing to spend-it took me just over an hour and a half to reach the total below (though a big chunk of that was me doing nothing because somebody else took over for a bit)...
...and of course, things go on autopilot once you reach a certain point, as it's pretty much impossible to break the combo when the floor is completely covered in things that make the turtles keep bouncing forever. The only reason I stopped this particular combo is because there was a thunderstorm rolling through.
The other, as far as I can tell, is an engine cap (if I'm remembering right, it's 2147483647-it's probably a memory-based cap, based on stuff you can read here). It's a bit of a shame, but it's kind of inevitable.
Anyway, if you want to blow a lot of time in pointless fun, Epic Combo is a great game for it.
Although if you dislike cruelty to turtles, you might want to give it a wide berth.