I get the impression 'The Portal' would like to be a bit like 'The Ring (1999)' - and I can't knock that aspiration. The Japanese original and American remake are master-classes of weird horror. 'The Portal', alas, isn't directed with anything like the skill or comparative restraint. Also, where I am a big fan of low-budget horror, the lack of finance seems to inhibit the ambitions of those behind the camera almost as much as the comparative lack of sophistication.
There's an interesting Lovecraftian central idea in the titular Portal, and some terrific gore involving exploding heads. But Serge Rodnunsky's writing is frequently undermined by his directorial choices. He appears to desperately want to keep things from getting boring by constantly introducing new characters in various shades of jeopardy, but succeeds only in confusing and disorientating the audience. As a result, the film comes across as badly edited, disjointed and frequently incomprehensible.
There are good ideas here, and that's the frustration. Set-pieces which could have been visually arresting are destroyed by constant fast cuts and close-ups. I imagine this comes to down to inexperience, and the desire to make every second matter.
As for the actors - Michael Madsen (Azirra) growls and poses his way through his dialogue, Stacy Keach (Hafler) does what he can with his lines, and Jenna Zablocki (April) is convincingly terrified in a variety of ways.
Once you are aware of the limitations on offer, you can enjoy 'The Portal' for what it is. My score is 5 out of 10.