OP solved it, closing

In general it's not possible to run random tests locally since they are not available until you solve the kata. Ideally tests logs should be more explicit and give you the input your code fails on. In this kata, NASM tests seem identical to C's tests (on Codewars, afaik NASM tests are always written in C), so if you solved them in the latter you may be able to do something useful locally.

Sorry, the time out is fixed by CW. Furthermore I can't reduce the tests when some people are timing out...
11 people passed the Shell kata so it's doable in the given time. There is a solution that takes 1275 ms and there are some below 2000 ms. Cheers.