Awesome, just awesome.
The two 'classes' you can play (Elements and Spirit) provide quite different playing experiences, with some levels being easier for one class than the other. Overall the levels are paced really well and rise gradually in difficulty for both classes. On top of that you can choose to focus on the magic aspect, or go a completely different route and stack physical damage in a tank/fighter build. All three ways to play are great fun, I recommend playing through the first file or two trying each of the three, then commit to your favorite for running the endgame content.
The system is really intuitive; the help files didn't work for me (I didn't have ZZT.DAT in my folder, so external help files don't load) but the game does a good job of teaching you everything you need to know.
The combat is really special in this game. I've :shot and :touch-ed a lot of objects in ZZT and I've never had a game where a true melee fighter (all upgrades focused on absorbing damage and sword upgrades) is not only an effective and viable build, but is equally as fun to play as the magic classes. Best case scenario is usually too easy/too hard, or one is fun and satisfying to play and the other is not.
There is staggering variety in enemy behavior, every environment is richly detailed and distinct with some really nice decisions as to palette. The ornamentation needs special mention as the decorations (statues, wall coverings, light sources) in every level are unsurpassed. You will find their equal in very few ZZT games indeed.
The difficulty curve is really on point; I purchased the last item right as I reached the final boss.
There are very few typos and bugs, and nothing game-breaking. Not a drag on the overall experience. 5.0 / 5.0 Top-tier ZZTing.
All in all, if you have any interest in ZZT in 2020, this is a must-play, no question. If you hang out in the museum of ZZT discord, ask me about the custom ZZT executable I whipped up to play this game, it maps keyboard keys to the common tasks (cast spell, drink flask) so there are fewer interruptions to the game flow. Check it out.