I see what you are trying to do here, and I think some minor adjustments here and there can improve the game quite a lot. For example, I think making the map a bit smaller would bring the pacing up quite a bit, and thus adding a bit more tension to the gameplay. Also, some visual effects would be nice too, like indicating player damage is a huge one as currently there is no way other than seeing the health text go down.
But let's not be too negative now. I'd say with more work the game would be much better and enjoyable, so keep up the good work!