I think I played Crystal Caves when I was 5 or 6 years old, along with Monkey Island, Indiana Jones, etc. It is a simple platform game, a jump'n'run, where the goal is to find all the crystals in each level, along with your blaster to protect yourself against monsters (snakes, robots, dinosaurs, one-eyed-things, two-eyed things with a big mouth, falling rocks, snakes whose carcasses take 1 HP etc. Some monsters have to be approached very carefully, and with planning. An that is about it, roughly. The mines are a hub, from which you access different caves, and this is where you save your progress. CC1 I remember very vividly, the levels are saved in my 5/6-year-old's mind, and I beat it quickly after I bought the game. CC2 and 3, however, are very tough as I am playing them for the first time. It seems the developers went wild, and thought how to make each level as hard as possible. The fun is not that big as with the first one, although I still like it. You just have to "git gud". I'll finish with a summary. If you: A) love pixels, and want to play old games, and witness gaming history B) want to show your children how games were back in the day C) want to have fun and challenge yourself get Crystal Caves. And with time, get good at playing it.
I picked up Unepic last week after solid 200 hours in The Witcher III + expansions (late starter). I wanted to have a break between Wild Hunt's new game plus - so for at least a year I am playing games from my library. Unepic drew me closer with its premise: a guy lands in a castle God knows how, names an evil spirit Zeratul, greets others by saying "En Taro Adun", references other games, events etc. I had medium expectations, expected to find copper, and I found gold. I am approx. 75% into the game, and I enjoy its challenges, the enemies, and quests make you think about their solution. For a low price you'll get at least 30-40 hours of enjoyment. Some critique may be directed at the inventory, which takes time getting used to, and is a cluster of things you need to check out with cursor/mouse before you know what it is (sometimes I was looking for a thing for 1-2 minutes before I finally found it. So, "no ragrets" for me, and I am off to explore the catacombs.