Good job man! Sounds pretty good so far!
The tyrant looks pretty heavy, so I think a lower pitched clip per step was the way to go. If anything I would just shorten the length of the walking sound a smidge, but it's not necessary.
As far as alien sounds go, which other ones were you planning to make sounds for? I'm working on some myself, so teaming up to create some unity doesn't sound like a bad idea.