Interesting idea for a game. here's my feedback
- I like the randomly generated levels, it gives something interesting to look at
- The pacing of the game is really slow. it takes way too long to get the first upgrade
- ux of the upgrade screen can be greatly improved by displaying prices next to the items, so you dont have to click through each upgrade to see what you can afford
- would appreciate some more graphical juice (screenshake, particles, etc), because otherwise the gameplay is rather boring
Nice work!