One map of the horde mode implemented in the full version of V.R.G. is now playable for free.
V.R.G. is a FPS along the lines of the Boomer Shooter format with sprints and wall runs.
The horde mode rules are similar to Resident Evil's Mercenaries, with 150 enemies to kill within a time limit, and the time limit increases based on how the enemies are killed.
It is suitable for those who are used to FPS with resource management like DOOM Eternal. However, there are sprints, so be aware of that.