The TemTem character creator is pretty lame. (Just saying. Haven't even gotten my starter yet. Trying to play the campaign with a friend.)

Headlander is probably a 6 out of 10. (+.5 if I add 'I liked it' bias to it.) Decent quirky Metroidvania. Combat and puzzles are easy to deal with. The map is good enough, and its pretty easy to level up. The story, sidequests and many of its upgrades are pointless. And the final level feels thrown together (with a random ass Simon Says minigame in it), and the final (2nd) boss was defeated by me smacking it across the head and then promptly going to a corner of a room where the boss couldn't hit me with any of his attacks. Rinse and repeat. Oops.

But if I were to recommend a Metroidvania for 20 bucks. I'd say Islets has been quite a charming and breezy experience thus far. With enough challenge (in its platforming sections and bosses specifically) that it doesn't suffer from being too easy. (Like Headlander, or Haiku The Robot.) The map, easter eggs, character interactions, rewards, upgrades, monster variety, it has everything and its doing them pretty well too. If anything, its grab bag style of game design, feels a bit unfocused. With the character feeling a bit floaty (and twice as fast as most action platformer MC's.)

However, its probably a good game, when your biggest/most common criticism is the NPC's dialogue is often amusing. But they [b][i]feel[/i][/b] like NPCS. Some repeating one line, usually boss lore, long after it mattered. Other recurring characters will speak about events in the wrong order. (Because you happened to show up too early/late.) For example, the rival makes a witty pun about how he somehow managed to connect two of the islands (the gimmick of the map) in his sleep. [i]But by that time, I already connected three of them.[/i] So the interaction feels unnatural.

But unless it falls off [b]hard[/b] in its second half. I'd say its well worth it. If you've finished Hollow Knight. (Or want an easier/adjustable difficulty version of it.) 

Edit/Update: Islets was honestly a lot of fun for the ten hours I spent with it. Though after becoming more than a bit overpowered, (which almost seems intentional the way you're forced to fight multiple previous bosses, just to completely kick their ass.) The final boss and the charm in its characters pulled through. And it even managed to feel rewarding to 100% the game and find all its secrets. Strong 8 to 9 out of ten. Liked it all the way through. Small bugs and gripes aren't even worth mentioning.