Not particularly good at all.
You didn't explain how the hell to shoot, you didn't create much build up in difficulty, we saw many factors of variation, but only expressed once in one level throughout the game, there was no difficulty buildup, the spaceship was just ridiculous (especially with the change in control scheme) and the lava is glitched to knock out hearts, but to not kill....I just jumped on back out of it and continued.
Okay, sure, this game is your first but it does need work. If you worked on it more than a day then the game would perhaps excell more and if you put more factors into it than the gameplay would be more decent. This review isn't to make you feel bad, but to do as a review is to do, and help you revise your future games.