On one hand, this happens already. Many perfectly respectable streamers and sites use affiliate links for stores like Amazon to get a small cut of sales. Engadget's product database also has them. It's a way to make money, and doesn't necessarily make something unethical, especially if everything, good or bad, is linked.
On the other hand, Chrono's a bit different. It only sells a single game, directly from the developer. And it encourages its "influencers" to promote that game. Streamers are likely to be honest with their viewers about their opinions on any particular title -- once you break that trust, you're unlikely to get it back -- but that's not really the issue here. The issue is that it's pushing streamers towards covering a game. Or, to put it another way, it's paying for coverage. By using the bait of financial reward, and by only offering a single game, Chrono is offering its partners a singular option: promote this game, or make no money.
Right now Chrono seems to be offering well-known, older games. So far it's sold 2014's The Banner Saga and last year's Broforce, which does temper the issue slightly. Most streamers will have covered these games already, and can simply point to the videos and / or give the relevant affiliate link out. It's difficult to be upset at someone monetising pre-existing content. But what happens if Chrono starts pushing a title they haven't streamed -- could streamers be tempted to highlight something just because it's the game of the day?
Chrono has an interesting concept. It's one that understands that a lot of people get their gaming information from Twitch and YouTube rather than a journalistic entity. And everyone has a different set of ethics, so there's not really a right or wrong answer here. I'm not particularly comfortable with affiliate links or sponsored content, for example, but I accept that they need to exist to fund sites, and they don't actually affect my job in any way. Many others feel the same.
That said, buying from Chrono could be a great way to support your favorite streamer. It's had some huge discounts on two very good games so far, and developers seem super happy with the results. So long as partners are up front about their ties to the site, then it simply exists as another option to get some deeply discounted games. If not, then the potential for ethical quandary is strong.