Really a great work!
Adding the teleport and the callback to the only bullet really solve main design problems of one-bullet shotting games. It force player to do a quick but meaningful decision in a short time. a Clever solution!
And the game looks good and juicy enough.
BTW, the music is so cool! I am not very good at shotting game but I would love to hear the rest of it. I makes me try again and again!
And I come out another idea for this one bullet shotting game. What about a charging bomb instead of teleport? The boom's range is larger when you leave it alone longer. When it comes back to you, BOOOOM! Another risk and return solution, hahahah. I am just saying though^_^
Overall, like this game! One of my favourite for now. It should be in the last 100 games I believe.