most of the timeyou jsut die because you have to share your vision between looking at the screen, looking at the upgrades, try to figure out whta the paritally almsot unreadable font dsays for each upgrade.
and keep moving, which isnt easy when looking from the corner of your eye cause critters will literally spawn in front of you and dont exactly look too different from the background flowers busheds and such.
and realizing that you are touching something and getting away from it basially means half of the health bar gone in most cases