Crimson Dragon Slayer brings to mind the old gonzo days of gaming, like Rifts in my case.
Premise here is that your character is transported from 1983 to this weird world of Thule and transformed into the character you create during char gen.
Races range from your normal humans, dwarves, halflings and elves to less common infernal elves, pixie fairy princesses, reptilians, crystallines and robots.
The race examples provide enough diversity that it shouldn't be too difficult to homebrew more racial options without breaking anything.
Classes are more baseline with warrior, mage, thief and ranger. With the last two branching to different specializations as you level up.
The system itself is rules light, not as light as Alpha Blue, using pools of d6's for most things. Conversions from other OSR games shouldn't be too difficult either so this ruleset could easily be used in the OSR setting of your choice if wanting something a bit lighter but still not ready to go as far as Alpha Blue.
As a summary I'd say it is humorous, gonzo old school game with a slight modern touch in the lightness of the rules. And like with most Vengers work it is also a quick and light to read through due to it's conversational and humorous writing style.
[4 of 5 Stars!]