I couldn't finish this game. I wanted to, I couldn't.
It's so, so broken. So much of the time I spent in this game was me attempting to find workarounds to the (many) bugs which plague the experience. Every time I shift+tab'd to use the Steam hub, for example, the game would get stuck on a pause loop and I would have to restart it. This happened to me about four times. This, alongside many other bugs kept me from enjoying the game as much as I had hoped to.
In addition, some of the transitions and effects are very jarring. Deaths and respawns are separated by a single, quick cut. Certain guns make the entire screen flash white. Many of the graphical glitches proved distracting. There was a lot of eye strain. I only played this for two hours and I have a headache.
I really liked some of the character mechanics. Every time a new character or item type appeared, I found myself admiring the creativity behind it. I wasn't much a fan of the implementation for many of them, but that opinion may differ from person to person. The game's funny, I really loved the cutscenes (though some of them had graphical glitches cutting off part of the screen). Humor is definitely something the game was not lacking in.
I backed this game on Kickstarter, and I was in the Beta. As far as I remember, a lot of the problems I had with the Beta still exist in the game. I wish more had been done to fix the pre-existing issues rather than to add to the game length. I wish there was at least a level skip or something so that I could skip the particularly frustrating levels. The frustration is a beast of its own. I don't disagree with the game's controls, but the level design does. I still don't know how to work the jetpack very well. Many of the levels are designed to be difficult, but usually come off as annoying. Many of the bosses have little-to-no real challenge, as dying will just instantly respawn you to a nearby area. One boss forced me to stay on platforms, which gave me issues when I glitched through the geometry every other life. I don't know why this game even offers a windowed mode, as it requires quick mouse movements and clicking outside of the screen definitely causes issues.
I don't want my money back or anything of that sort. I paid the developers to make this game, and that's what they did. I'm happy for their success, and I'm happy to have been able to contribute to it. I don't want to call it a bad game, because there are still elements I enjoy about it. I love the theme, I love the way it's presented, and I love the interesting mechanics. I just wish that it weren't so broken, and that a few tweaks could be made to the design.
If you're interested in this game, I recommend trying out the demo beforehand. It's really, really hard to enjoy this game if it's too buggy on your computer.