So while I was trying for speed runs (my fastest one has a glitch where it skips the beginning part of level 3), but while I played the other levels, I noticed that the minimum possible time to end level 1s boss is at 1:28, (the boss only taking 12 seconds) this includes spam shooting and never getting hot once. In the opening bit for the lvl1 boss, you can jump and fire two shots, both hot, and then roll under the first attack, the second you can land 1 and roll, and after that you can land between 2 and 4 shots killing the boss. Just thought to share that with you all.