Gemcraft
/Things that it does beautifully
The concept of each gem having a property, and your ability to mix those properties at whatever ratios you want, is very freeing, and just neat
The idea that you can choose to increase the number of enemies (and thus challenge) coming at you creates a really great risk/reward, and encourages you to push yourself, if the pace ever starts to get a bit slow (because you are crushing too hard)
Because the game is always pushing you to up the difficulty, you’re more likely to be in situations where you’re at your limits, where you’re barely getting by; this increases the drama
Similarly, with the heightened level of drama that one tends to see, is the need to min/max and make clutch plays. The game supports this well by having things like swapping gems (and active action the incorporates elements of timing) and Gem Bombs (which allow you to “panic”, and perform inefficient actions for the sake of your larger goal)
The level of meta-progression is really out of this world, and it can all be shifted around at will so you can try any number of approaches to any situation, and meshes really nicely with the idea of having different types of gems. Different gems are going to benefit from different strategies, and so it encourages you to experiment
I like how you personally build the towers, the walls, and the gems. They are all separate things you have to purchase, and have escalating costs, so you have to balance how much you buy of each. You create a balance of gem strength, vs gem count, vs maze quality.
Part of what helps the game maintain its economy so well, is the fact that building towers and building walls are completely separate things - towers are 100% for increasing gem count and 0% for maze building, walls are 100% for maze building and 0% for increasing gem count
The way they make the Talisman system into a little puzzle is so cool, it’s like turning inventory management into inventory tetris, except better, because the interlocking of the pieces means that it takes actual thought
Wizard stashes introduce a really cool challenge wherein you have to make some level of choice between focusing on enemies, and focusing on rewards. Another case of risk/reward
Not so Good
It’s pretty annoying how you can’t tell what kind of gem you have in a trap, beyond the colour (ie. you can’t tell what level it is)