So to be honest, I'd normally give this a 3/10 for the general feel of the movie, but I bumped it up a bit because I thought the concept and attempt deserved some bonus points. While it is definitely an amalgamation of previous time / space travel ideas and won't really provide anything new to any fan of that genre, I think this film had a unique flavor.
With that said, the rest of the movie was definitely lacking in polish. There were a couple scenes where you could see the shadows of the film crew (I thought someone with a gun had walked into the room, but after rewinding I'm pretty sure it was the boom operator), guns with suppressors aren't suppressed in the audio track, stuff like that. The acting is mediocre at best, but I wouldn't say it's horrible. The major issue is the execution of the plot. The scenes seem to jump around a lot in time, and it really wasn't necessary. It was hard to tell if they were trying to go for some Memento-style reveal at the end or if they were trying to trick the audience into thinking related things weren't related and vice versa, but failed to do both. It's definitely not a movie to mindlessly watch, because you'll lose track of what's going on very quickly. But if you're desperate to see something that isn't the same Hollywood blockbuster as last week, then this might do it for you.