itch.io

This is my old project similiar to yours, try using PATHS make WALLS make boss spawn other enemies... make other phases of boss fight because after 30 seconds of play that was boring.

Try to use engine like Construct 3 (it is paid but not really expensive, and it have trial version) or Unity

Really cool music pack... soundtrack is very important part of game but most of indie developers do not know how to make good music :D