As someone who hasn't really seen much of Gavan beyond the Gokaiger and Gobuster team ups, I think this was a great way to introduce a classic metal hero character to a modern audience. I think anyone who enjoyed Gokaiger VS Gavan will probably end up liking this movie as well.
A few things that stuck out to me:
-Space ninjas? AWESOME!
-Master Brighton, despite the silly sounding name looks quite bad ass. I love how his armour looks, especially his helmet.
-Speaking of the helmet…there's a mask underneath his mask? MASKCEPTION!
-The scene where they were in Makyuu Space was great, really loved all the Yay! Scenes and Geki trying to hit on that woman…one thing I thought that was odd: If Makyuu Space applied the lizard guy's power…why bring them back to the real world and loose his one big advantage over them? That kinda makes that whole scene pointless if the main fight was going to take place in the real world to begin with…
-During that part where Geki kept shouting Itsuki's name as she was being possessed I kind of wanted her to say "There is no Itsuki, only Don Horror!"
-Was there a specific reason why they needed Itsuki to act to act as Don Horror's Vessel?