Good concept! Hiding the player outside the screen is really good idea for the topic.
I would suggest to have something like this as a pointer to know where the player is.

It's easy to conquer the game when always aiming at the red spot :-) I made it up to 1800 without any problems by doing excactly that while collecting the triangles.

It would be great to add some projectiles or more visual feedback for the player.

This game lacks player perspective, hiding out of the screen isn't my cup of tea, i would like to see player hiding behind some obstacles like boxes or other similar objects. I've played it few times and managed to score about 600points. Good Job overall!!

The best I could do was a highscore of 1250! It is a fun game and the core loop is interesting but to be able to see the bullets would be really cool. :)

It would be better if you could see bullets

It would be nice to see bullets =) I liked the idea of stealth!

It would be better if there is some indication where is player, but idea is interesting!