Made by me, it is advisable to use the v1.1.3h3 version, otherwise it may not work.
Enter the Gungeon: Cheat Engine Table (+1: Immortality) [v1.1.3h3] {BlackBW} Free Download
Activation on F7, or by clicking on the square.
Works on the principle of freezing hp on 99 hearts.
ATTENTION: Before activating, you will receive damage (damage), otherwise there will be no activation.
You can download Cheat Engine from our server here.