A satisfyingly graphic introduction to the incredible violence of the grim dark future and the Emperor’s chosen.
It neatly establishes the in-universe pecking order of human vs. post-human, with the Astartes dismantling their opposition in short order. It also showcases the more esoteric aspects of the lore and the greater threats facing humanity.
However, while this short amply demonstrates the power of the Space Marines, it also highlights their weakness as a storytelling device. Stoic, honour-bound warrior monks with little to no personality beyond their varying levels of savagery or tactics in battle.
If the Warhammer 4k Universe wants to succeed on screen, it will need to deliver a lot more humanity than taciturn giants undertaking various acts of sacrifice and mutilation, no matter how gloriously realised.