The game itself is not too bad, but I ran into the following issues:

1 - Certain levels (level 2, 10 and 19 for example) I took damage right when the levels started with no enemy collision. This caused me to die right when level 10 started on my first playthrough as I only had one heart.

2 - On my first two playthroughs, when I died the death menu would not let me select restart level. As such, I picked level select the first time and selected the last level it would allow, but when the level started the death menu was still up. I picked main menu that time and picked campaign (i did not click erase data) but at the level select menu the only levels available were tutorials A and B. On my second playthrough, when I died, I picked level select picked my level, still had the death menu, picked level select again and again my progress was gone and only tutorials A and B were available. On my third playthrough, restart level worked until I ran into the issues in issue 3 below, so I tried level select, I had the same issues as above.

3 - Level 19 would not let me pick up the key. The sprite behaved like a wall and I could neither stand on the panel where the key was, walk through the key or retrieve it. Dying and picking restart level worked, but the sprites for the medicine bottles did not reset and I still couldn't pick up the key. Dying and picking level select recreated the issues from issue 2 above. I did not replay again after that.

If those kinks were worked out I would have given at least a 4 star rating.