Hmm, quite the interesting twist on tower defense! It's a lot to get used to at first with the whole merging system and learning what towers do what and dealing with randomness and the positives/negatives for wave rewards and so on, but there was a certain fun and addictive novelty to seeing all the crazy towers you randomly get and what the next level of merge is going to be and then just blasting away and enjoying the chaos of your various towers wiping through waves!
I gotta say, though, that at the end of the day, I didn't find myself getting that far. I do think the idea is novel and that there is some fun to be had, but I just ended up getting bored quite quickly due to the lack of variety and feeling of not being in control or needing to strategize. Don't get me wrong, I think there is some level of strategy in here that can be done, interesting improvizations and saving up to then pick a 100% spawn wave to do a big merge and such, but it just didn't feel substantial enough compared to a typical tower defense where you have all your tools and there are all sorts of different layouts and enemy units and rule changes you can puzzle it out. I also wish I knew how some of the skills work, like fear and Xx damage (what does fear do, and does Xx damage affect other units or just the unit in question, and so on). I could definitely see other people having a lot of fun with this though, and I still had a good time while it lasted!