Oh wow, can't believe I missed that during testing. Luckily I used byte as the lives data type so you only get 255 lives on playthroughs past the first at present... Fixed now on my end, will upload the patch after the voting is over.
Regarding the over/undershot thing, was it trouble seeing the arrow and its white trail/heart particles during flight, or trouble seeing the arrow once it hits a wall/where it hit the wall?