I think visually the atmosphere was well done, but not including audio really made the atmosphere take a hit. A little spooky ambience and the clanking of the monster's legs as it got close to you would've added so much, I think.
I would've appreciated a checkpoint after clearing the purple door considering how easy it is to get caught and killed by the monster. It seemed that the point of the first part was to establish the atmosphere and teach the player about buttons/doors and pulling objects, so that isn't lost to the player if a checkpoint is placed at that door.
The pulling mechanic I think is a really cool way to try and obstruct the monster but it's inconsistent to use especially in the heat of a chase. It seemed that the problem was that you could only pull stuff when you're looking at it. If you could pull things behind you it would be easier to use.
Overall I think the idea of pulling and pushing stuff to obstruct the monster has a lot of potential so I'd be interested to see what you could do when the idea's more fleshed out. Nice job!