The Valentine's event, like all events in this game I've done, used no more energy than you can get through "natural" regeneration—but if you don't want to pretty much abandon everything else you're working on, you better have alternate energy sources like spice farming. The bottleneck of this event was pavillion II, so basically you'd 1) keep pavillion II harvested (not hard with 16 hours capacity), 2) spend that scent on bushes, 3) spend the glitter on tables, 4) when a table is finished, get 4 snacks from pavillion III. If you're on "natural energy", there wasn't any waiting. The unique thibg is that players with appropriate resources could speed up most other events, but not this one. It took less than 2 days to get 1 ghost, and many players did that. I got all 3, and had no issues.
actually, I needed to 1) use Bluetooth mouse to focus game, 2) use bluetooth keyboard to play, on Android. (Tapping would not focus.) The game was fun after that!
Update: I did play all 40 levels and some bonus levels; two of them crashed the game because they're too big/have too many units. By the end, I'd gotten used to it: the AI had become more predictable, and the novelty had worn off; the AI didn't get smarter, but I don't think the game got much more difficult. It's still a decent game, though.
Medieval Conquest is the 4th "Slay" clone I've seen, and has the best presentation: nice graphics, a good tutorial, animated units. However, as a strategist, I'm really looking for a good AI. Konkr.io (also on Kongregate) is the best, and it lets me enable the hard AI right away. Here in MC I've played the first 20 levels, and the AI is a pushover for me. The game adds a challenge by setting bonus tasks. I can progress in the game simply by winning ("destroy all enemies" aka take all towns, making the remaining units neutral). But to get 3 stars, I need to do "unstrategic" things such as not taking any towns until the end, or not losing a single unit, and that does make it somewhat challenging.
Is it fun? Meh. It's competent, it's playable, but ultimately it feels like I'm playing easy maps with a hand tied behind my back. The upshoot is that, while the game is decent and looks nice, I'd rather go back to konkr.io.
This game is mouse/touch-only and works on mobile (Android).
The timer kills it. "Keep you addicted for hours" should be "minutes". The art is beautiful, the concept is nice, the scoring is awkward. Give out 1-3 stars based on time taken, and let users revisit levels; I like that they're randomized, so it isn't about rote learning. Then a slow user can go through teh game with a star each, and then work on getting more stars if they enjoy it.
The game has no stacks, and only simple pairs, so there are no wrong moves, and the rules differ slightly from conventional Mahjong puzzles. That makes the difficulty quite easy. However, the interface is well done, and the game is fun to play.
 "Oceania")
 "Overlord's New Mansion")
 "Pumpking")
 "Idle Zoo")
 "Medieval Conquest - Turn Based")
 "Headspin Storybook")
 "I wish I were the Moon")
 "ZS Dead Detective - Walls can Bleed")
 "Master of Fortresses")
 "Apple Worm")
 "Escape From 26")
 "Blocky XMAS")
 "Halloween Mahjong Challenge")