This game was really fun!
There's a lot to like. First off, the art style reminds me a lot of He Is Coming, which is to say I really like it. The brighter monotone items against the darker background has a really nice aesthetic. Second, I thought the incorporation of the jam theme was spot on. I lost two of my lives early on and it created a ton of tension for the rest of the run. I really wanted to access the higher-tier items, but having only one life meant that it was really scary to go up against unknown stat blocks. Third, the merge mechanic was a very clean way to balance out the risk-reward equation. Sure you can merge all the way up to red, but it will take you forever if you're not taking any risks.
Awesome work!