Undeadblock is an interesting game, but quite resource-intensive. Not every PC will be able to run it
It is indeed not that intense but at least we need an average gpu to run it, please bear it in mind the zombies are spawning from every side.
if we are using an old gpu, we will see a lot of glitch when we are playing it and at some point it will freeze.
tried it a few times, it is smooth in the beginning but when the zombies are around 30+, It is starting to glitch.