The difficulty level in Ghosts ‘n Goblins Resurrection matches that of the classic original games, but it can be alleviated by collecting the umbral bees that you can find throughout the levels.
These umbral bees are hidden, and you need to walk to a certain place to trigger their appearance; once they show up, they can require some fast footwork to collect. The number of bees you can find is indicated at the beginning of each level, and they can be used to upgrade your hero Arthur with spells and abilities.
The Execution Grounds is one of the first two levels that you can choose to start on along with the graveyard. Collect the bees from both levels for maximum upgrades.
Here are the locations of the four umbral bees in the Execution Grounds.
After the first two grave traps you see, when you reach the falling ruins, head up the ladder with a tombstone at the top and the bees will appear. The bee will float to the right of the screen and you will need to chase it down or it will disappear once it hits the tree.
After the set of four guillotines, you will reach the platform that breaks off and begins moving. Once you get to the first guillotine on this platform, the bee will appear above you. Reaper enemies will continue to spawn around you, so be careful here.
Once you reach the waterfall area, head up the path to the left, take out the big enemy (if it spawns) and the vines, and check above for falling cages. They don’t hurt you, but they can leave you vulnerable to the vines.
As you go over the waterfall, the bee should appear on the platform just past it. There’s a falling cage just above this ledge, so you’re likely to get trapped by it, but the bee will fly into it, so you will be able to jump and collect it.
At the chase section, triggered on the bridge that breaks where the pig enemies are rolling at you, jump off the end to get on the big platform at the bottom of the ramp. From here, jump across to the platform furthest to the right and the last bee will appear. Missing the jump at the end of the ramp will make getting this bee near impossible, so make sure you make the first leap.