Arturia Microfreak is an experimental synth designed to be a quirky alternative to more conventional synths. It's got a touch capacitive poly-aftertouch flat keyboard which is unique to this device. Do note though that the keys can go a bit funny over time due to humidity and finger heat. Benn Jordan mentioned this in his gear tier list video where he says the sound from the Microfreak is amazing, but he'd never truly taken to the keyboard itself. I think it's fair to say it's an acquired taste. You sort of have to try it to know though.
It's four-note paraphonic, and whilst the construction is okay, I'd honestly take a bit more care with this than something more rugged. A Desksaver is going to be worth having for this one.
As I mentioned, the sound is really quirky and interesting - you've got a single digital oscillator with an analogue filter, and modes covering everything from wavetable to granular, formant, and way, way more. In my experience, the sound is a little thin and benefits massively from an effects pedal, as it doesn't come with any built-in effects. It's just a single raw oscillator, so it can sound quite dry.
It's pretty easy to use - you choose your oscillator type and play with three macro controls, which isn't the usual synth workflow. But actually, it makes experimenting with sound design straightforward, especially for beginners.
Overall, the Microfreak is a very solid, affordable option for anyone wanting hands-on synthesis or something genuinely different. It's not just for beginners - pros find that it has its uses too. The most obvious alternative I can think of has got to be the Minifreak, which has multiple oscillators, built-in effects, and a proper 37-key keyboard. If you want an all-in-one sound design workstation, that might be worth saving up for.
But for the money, it's very difficult to fault the Microfreak - and there's very little out there like it, especially if you like its quirks.