Just look around.
In the source code of the page, we see a large number of calls to the function __. Let's check what this function does.
Turns out, __ is just the same as fromCharCode! So the huge blob of code is simply constructing a string from the ASCII values of each character. Let's see what this string decodes to:
if (window.addEventListener) {
var index = 0;
var konami = [38, 38, 40, 40, 37, 39, 37, 39, 66, 65, 13];
window.addEventListener("keydown", function(e) {
if (e.keyCode === konami[index]) {
index++; //valid key at the valid point
if (index == konami.length) {
document.getElementById("valerie").innerHTML = "01111011011011010110100101110011011100110110100101101111011011100111001101110101011000110110001101100101011100110111001101111101";
}
} else {
// incorrect code restart
index = 0;
}
});
}Looks like if we correctly enter a Konami code, we get a binary string. Decoding this string from binary gives us the flag.
>>> format(int("01111011011011010110100101110011011100110110100101101111011011100111001101110101011000110110001101100101011100110111001101111101", 2), "x").decode("hex")
'{missionsuccess}'{missionsuccess}