This game is very well done. I like it a lot. The visual with the lights were really special.
I spent 30% of the demo thinking that "power" was the ammo, and it wasn't goin down because it was bugged, so I was shooting sparingly. Once I got the first secret upgrade I was like ohhhhh and infinite ammo it is. It made the game much more enjoyable once I was firing almost constantly hehe. I was having so much fun with the rapid fire that I discovered that you can charge just after beating the boss.
Not being able to return to the start left a bad feeling of not exploring everything. The boss was alright, a bit on the easy side, but I guess that's perfect when it's the first you will probably encounter.