Thanks for playing and the for the feedback, I agree health packs would've been nicer for the game and it was what I was planning but I had to make do with the regeneration in the end due to time constraints.
Also as for the boss the blast shouldn't mean that it's dead but that it is near death, I've made the enemy health stop at 200 points and for the health bar to stay visible, hopefully this will hint that there is still more needed to kill the alien, also modified the alien to be able to see past the pillars so the player can't hide there instead you have to run & gun.
Thank you for your input your input, it will make the game better for future players.
All updates have been published as a separate update from the initial jam submission.