The game is visually well-designed, with appealing environments and enemy sprites. The soundtrack is serviceable, although it doesn't particularly evoke the original game or any other Resident Evil title. However, the gameplay is quite rough. On normal difficulty, the game lasts a mere 3-5 minutes, while on professional difficulty, it extends to 25-30 minutes, which was the first difficulty level I played.
Inexplicably, the developers decided to make professional difficulty an insta-kill mode instead of maintaining the three hearts available on normal and removing all the healing herbs. This leads to an extraordinary amount of frustration and repetition. Every enemy has a fixed spawn trigger or placement on the map, with the sole exception of the female ganados, which spawn randomly from both sides of the map. If they spawn in a certain sequence, especially near plaga enemies that cannot be killed, death and a checkpoint reset are guaranteed.
I understand that this is a simple 8-bit recreation of Resident Evil 4, and a decent one at that. However, the professional difficulty feels tacked on and completely thoughtless, making the game a chore and only serving to highlight some of it's shortcomings. I recommend playing on normal difficulty instead, as it is much more enjoyable.
The final boss encounter is mediocre. While the environment itself is visually satisfactory, and Dr. Salvador's and Ashley's sprites are well-designed, the fight itself is rather uninteresting. Dr. Salvador's hitbox is frustrating to deal with, particularly on professional difficulty. He can turn around abruptly, so if you're jumping over his head to get a few shots in after he attacks, he'll immediately face you, causing you to touch his chainsaw's hitbox before you can land, resulting in an instant death. Moreover, he cannot be stunned in any way, either by persistently shooting his face or his chainsaw. As a result, you must resort to baiting his attacks and jumping over his head to shoot his back a few times. It's a dull way to end the game, but I found it somewhat satisfying nonetheless.
If this game had a way to stun enemies, a shotgun, flash grenades, and a rebalanced professional difficulty, it would be a masterpiece. But for what it is, it's a perfectly enjoyable experience (on normal difficulty) and a commendable effort.