So much to love about this little game! I really enjoyed your self made SFX and the cute hand drawn art style. So much of the mechanics of the gameplay made it enjoyable to keep playing. I too had trouble with the spikey enemies. I did figure out how to kill the first one, so I could get to the awesome level select and collect some keys, but in the levels they were so much harder to kill. The shield concept worked so well with the bullets too. So much you could build on from in this game because the gameplay mechanic is there. Nice work!