Reasons that you couldn't join Cethic collab:
Too slow
NO action
Probaly tweens
Not even well made
That tests maybe help you a bit:
Walking: http://www.newgrounds.com/dump/item/35d4d4a7410e6ca5b02a306eb1dbfe3c
Shooting: http://www.newgrounds.com/dump/item/946cd473bcd9e9bcb98a4530802b778b
Moar action (not finished because i lost the file): http://www.newgrounds.com/dump/item/08468a60c924396c2711133834412daf
Croude
You can't join in Cethic's collab
He respond on your comment - No,you can't join
You need more practice and tutorials watching