Pros:
+ fresh setting with a unique swap mechanic
+ combat system is varied and transform mechanic offers a large variety of options
+ visuals are perfectly fine and the music is okay
+ some memorable NPCs and funny writing

Cons:
- economy is completely busted: meta-upgrades take forever to unlock
- bosses are brick walls that can only be beaten by grinding for meta-upgrades
- bosses have no variety, you will fight the first boss more times than you can count
- action frequently gets confusing
- difficulty is generally high but differs wildly between stages
- head upgrade mechanic is often useless due to lack of resources
- usefulness of heads differs wildly, with many being unfit for boss fights
- important mechanics are largely unexplained ingame (inscriptions, gate codings, buffs)
- skills don't reset between maps
- status screen is cluttered and confusing to navigate
- "enemy gained XP from your defeat" message is just plain idiotic

Playtime: Roughly 8 hour, which is really more than enough.

Blagic Moment: Not playing for a few days and realizing that you only return for more grinding and little else.
Best Head: Werewolve. One of the more useful ones.

Verdict:
Although Skul tries hard to add something fresh to the genre, this rogue-lite is a middling, time-consuming affair that will frustrate you far more than it will reward you. The endless repetition of stages, level set-ups and bosses combined with brick wall bosses make for a huge slog, and the innovative head swapping mechanic and exciting combat are simply not enough to elevate this one from the deluge of similar - and often better - games of the past few years.

I decided to abandon this after reaching the penultimate boss and felt like a huge weight had been lifted from my shoulders. Only play this if you have the time for it, because this game does not respect it - or better yet, chose a better game from the dozens of options out.